Tuesday, 31 December 2019

Leaf Challenge: Regular Painting is Good for the Soul

It's New Years Eve and I forgot to do the food shopping, instead I sat in the kitchen and wrote my last post for the decade. It's all about snatching a little time each day to paint something small.  Picasso famously said 'Art washes away from the soul the dust of everyday life' so that can't be a bad thing to end the year on ....there's been a lot of dust this year! but another plus is that regular painting is the key to improvement. With this in mind I decided it would be good for me to power through some speedy leaf painting. Of course in an ideal world I'd love to spend more time painting but it's not always possible. Each year I try very hard to complete a couple of 'substantial works' that I'm reasonably happy with, sadly sometimes not much else is achieved other than demos for tutorials. So my self-imposed challenge last week was to paint a leaf every day within 90 minutes....'if possible' being the caveat.

Details from leaves painted during week one.
Why Leaves?
I love leaves! and it's the love of the subject drives the painter on to try harder to do better - and to never give up.  There are so many leaves too choose from, many are challenging with incredible diversity and detail, there's more than enough to keep a painter occupied for a lifetime. As Lucien Freud said ' it's what Yeats called the fascination with what's difficult. I'm only trying to do what I can't do.'
I hope to carry on with this challenge for a while and to be a better artist but being fickle, I can always swap to a different subject should he mood change.... for now leaves are good.  Here's the sum total of my efforts with some information on the process.



Green Photinia, leaf no. 1 This is a leaf with a deeply indented 'V' shaped profile - i.e. it indents at the mid rib. The light is coming from the right hand side. Yet note how the right side of the mid rib is in shade, so although the leaf catches the light near the outer margin, as it nears the mid rib it indents away from the light. Conversely, where to leaf bends upwards, on the left of the mid rib, the light catches the smooth surface, creating a distinct difference between the left and right side of the mid rib. It's at its darkest where the far left curls away from the light This left to right difference is a key feature of lighting that shows the 'V' shaped profile. 

I generally use a 4 or 5 stage process and bring the whole leaf up in stages. Top row: Stage 1. underlying colour (cobalt blue) wet-in-wet, the highlights are the most blue (not the shadows). Stage 2. Basic hue wash, (French Ultramarine, Winsor Lemon and Permanent Rose) wet-in-wet is used, the idea is to capture form from the outset. Work on one leaf blade at a time (here shown in 2 images). Bottom row: Stage 3. Add more selected washes, wetting/ dampening and adding colour only where needed rather than wetting all over. Use a slightly creamier paint mix, this selective approach enables me to retain and control the highlights. I also add that brown blemish with yellowing around it, the same colours are used to mix the brown and dropped onto a dampened area.  Stage 4. Modelling dry brush technique using a much creamier consistency of paint onto a dampened surface to deepen colour. Drawing dry brush is used on the slightly damp to define softer veins. Dry brush on damp creates a softer smoother finish but the water:paint ration takes a little practice to get right. Towards the latter stages I allow the paint to dry to a skin on the palette and use a damp brush to moisten, this gives me a much richer colour for detail.  I also pick out veins at this damp stage and sharpen up the serrated margin by wetting the edge and adding paint into the wet edge and blending into the main leaf blade. Stage 5, Fine tuning and tidying up, deepen where necessary using an effect that I refer to as 'polishing' using a very dry brush in a circular motion. Mostly painted with Betty Hayways size 4 and 7. The final touches using a size 2 Windsor and Newton series 7 miniature. This leaf took about 1 hour...if only they were all so simple!

Do try this at Home
If you are thinking of trying some leaves, don't worry too much about the time constraint or perfection but do try to finish a small work in one day.  For me, the objective is to capture the overall 'character' of a leaf; its shape, form, colour and surface texture. It's not so much about tiny details or photorealism but more about the 'feel' of the subject. Start to improve your observation and understanding of leaf shapes and surfaces within a very short space of time your drawing and painting will improve too. See previous posts by searching for the 30 day leaf challenge, which I completed several years ago.

Leaf no. 2. Another Photinia. Love the variation in these leaves. This is the red version found at the terminal branches, slightly weathered this time and curls back more, with less of a 'V' shape at the mid rib but still has some left to right difference and strong highlights. 
The process is  much the same as the previous leaf but with different colours.  Cobalt Blue first, then selective washes of reds and violets. The reds are: Scarlet Lake (warm) Permanent Rose (cooler pink /red) and Permanent Carmine (darker (warm red). Add some French Ultramarine to make the violet and a touch of Transparent Yellows in the mix makes those dark, almost black blemishes.


Finished leaf


Can you see the Light: Technical stuff
As a tutor one of the most common problems the I see in leaves is a lack of form, flat looking leaves result from poor or diffused light - poor light kills a leaf stone dead because everything is painted using mid tones. To bring a leaf alive you need light and shade (i.e. a range of tonal values). If you're a beginner, the best way of resolving 'flat leaf' problems is to enhance that light, exaggerate it in true Chiaroscuro Rembrandt fashion but use modern technology by using a fixed light source from a lamp. This doesn't have to cost a fortune, any angle poise lamp with a swivel head will do, then fit with a photographers bulb E27 screw fit, use 5,500k (Kelvins) which is the nearest to natural 'white' daylight and easy are to buy on Amazon or from photography suppliers, don't look in art suppliers for bulbs, many claim to be daylight but are not. Bulbs over 6000k give yellow light and bulbs under 5000K are blue, so will not give accurate colour. You also need the correct CRI, (colour render index) of 90 or above or as near as you can get. Bulbs with CRI over 90 are more difficult to find and you may have to settle for 80 but the higher the CRI the better the true colour.  Light from the upper front left if right handed and the right if left handed, although I tend to light from the side the I think looks best for the subject. Pin your leaf to a piece of white foam board and light from your chosen side, move the lamp around to create good contrast. Try painting in black paint or ink first to avoid confusion between colour and tone.

Look at Ruskin's tonal studies for inspiration, it's all about light and shade, note the dramatic difference either side of the mid-rib. Study the masters!

© University of Oxford - Ashmolean Museum From Ruskin's Elements of Drawing, watercolour and bodycolour over graphite click for reference 

Observe and Draw 
Make sure you get the leaf drawing correct, double check the typical features of a leaf and look at a few different ones if you're aiming for botanical accuracy, alternatively, you can just go with whatever takes your fancy, some leaves are more interesting than others, so choose wisely. Make quick notes on leaf shape, margin, tip and base, venation pattern and surface texture, measure height and width and note the widest point too as this can be a key feature, if you measure you can't go wrong. At this point , ask yourself what are you trying to portray, is it shiny, mat, puckered or hairy surface etc. Being accurate in your portrayal of any subject is important so never short cut the observation and drawing. Keep pencil lines minimal and light. I use a H grade for drawing.

Limited Palette with sufficient range of blues, reds and yellows does not impose any limitation on what is possible. I've been working with this palette for years. 

Painting Materials - what you need and what you probably don't need 
My palette is limited to primaries, this is the best way of working for me, it keeps it simple and I can shift a mix to warmer and cooler versions of the basic hue - look carefully and you will see how light affects colour across the surface of the leaf, this is where using three primaries really works because that colour shift is made so much easier by adjusting the ratio of colours in the mix.  There's no need to have the whole colour range from every supplier.  Heres my basic materials list for paints and everything else. With regard to paper, I'm not discussing Fabriano any more, yes there's a new one but I moved on anyway. I've  tried a few different papers in the last few years, it takes time to get to know them, I mostly used Saunders Waterford HP high white 300gsm - it's a decent enough paper which takes a bit of effort with the edges but is tough and the colour is good. Botanical artists tend to prefer hard gelatine sized papers, starch sizing is generally a little too soft. I'm a fairly dry painter and careful washes is the best approach and if you work dry, so you never need heavier paper than 300gsm, it's pointless spending money on the heavy papers if you don't need them and often they are not so smooth as the lighter weights ( Arches being a prime example, the 300 and 600 gsm versions are like two different papers). I sometimes paint on Schoellershammer 4G which is super smooth and lighter in weight but because work dry there is no cockling, sadly this is another paper that appears to be discontinued. Brushes, usually size 2 and 4 series 7 miniatures and a size 1 short flat synthetic there are lots available. I did switch brushes for some of the leaves, which were painted with synthetic Betty Hayways brushes, I used the larger sizes 4 and 7 which worked well, point and belly are good but the small sizes are less so and as with most synthetics the tip goes quite quickly but I found I could use the large sizes for everything, even the dry brush. Use an elevated drawing board so that you save your neck and can see what you are doing and finally, use a magnifier! x2 is sufficient, more magnification isn't helpful as you can only see a tiny area also excessive magnification hurst your eyes.

Starting to Paint
After making a very simple line drawing with as little graphite as possible on the paper. I begin with underlying colour, in green leaves this is usually blue, a high light value blue, such as Cobalt, Cerulean or Manganese. In red and brown leaves, yellow and violet can be involved too, so this can require an underlying blended wash of several colours. You will see this in the various step-by-step images.

Leaf no. 3 A shiny Camellia. The process: this time a blended wash is used first using Winsor Yellow and Cobalt blue. The rich green hue is made with Windsor Blue Green Shade, Transparent Yellow and Permanent Carmine. I also added a little Indanthrene blue for the darkest greens. This leaf was a big challenge in a short time, it took the full 90 minutes because of all the layering with the veins and dark shades. I used a piece of agate to lightly burnish between layers, which makes sharper edges easier. I could easily have spent another hour on this.
Finished Camellia

Work up the whole leaf, keeping the light with selective application of colour
I can't stress how important it is to work up the whole leaf in stages, this is how you capture the light and shade to create a dynamic painting.  If you try to finish little parts at a time, the end result can be quite flat and lacklustre, although it can start off ok, it often ends up disappointing ( I'm sure we all know that feeling). I work up all of my paintings in this way and the more complex the painting, the more important it is to attack as a whole. After the underlying wash I add colour selectively working on one leaf blade at a time. I dampen and add colour where needed, which avoids adding too much water and painting over the highlights, conversely, adding too much water in all-over washes flattens, loses highlights and creates hard untidy edges.


Leaf no. 4. An aged Oak leaf. Same approach but with underlying Transparent Yellow and Cerulean Blue in small parts, being careful not to overlap them, I carefully 'scumble' the blue in the highlights leaving some white, this gives the textured highlight, see first image. This was a difficult leaf and I can't say that I'm overly happy with it, having botched the highlight on the green. Have painted oaks before and used more warm violet in the underlying shadow layers so I think this might have been useful in the shade areas. Its Ok though but I'd approach it slightly differently next time, so lesson learned. The browns mix, Transparent Yellow, Scarlet Lake and Permanent Carmine with a touch of French Ultramarine, the green mix is made using the same blue and yellow. Looks slightly unfinished but I wasn't in love with this leaf.  

No. 4 Finished...sort of 

Depth and Detail
Once I'm satisfied that I've added enough colour using selective washes, which is usually only 2 layers after the underlying wash, I start to use different dry brush techniques. Sometimes I use a 'scumbling' technique for texture, I use dry on damp for smooth deep colour with creamy paint to 'model' the surface, for creating rich colour and shadows. I also use a 'sweeping motion' for long leaves and a 'drawing' technique on damp and dry for detail and finally a 'polishing' circular motion which is the driest, and creates the shine. I use much the same techniques on vellum but with fewer washes.

No. 5 Holly. Can't beat a challenge and holly is always a challenge! It's dark, shiny, textured like leather and with points that stick out at all angles! I put the initial blue wash down, using Cobalt and Manganese Blue, I love the manganese for those electric highlights!  Next I 'scumbled' on the green in patches, working between veins and into highlights to give that textured appearance of an old dark holly leaf, younger leaves are lighter and slightly smoother. This is a very dark green leaf, Indanthrene Blue, Transparent Yellow and Permanent Carmine were used. The initial selective washes of green were more of a yellow biased lighter green mix, it looks messy but stick with it. The later colour is dry brushed on, it has more blue and is darker, so, a more viscous mix of paint. 'Polishing' it on with a dry brush smooths areas. The brown mix for the blemishes is the same three colours just start with the red and yellow and add blue until you achieve the correct brown. The approach is much the same for all leaves in terms of stages though, keeping the highlights is vital in holly but they're a stronger blue than you might imaging so be brave with the initial wash, it pales away against the dark green. I used the agate burnisher between layers to shape up the edges. 
Leaf no. 5 Holly finished 

What you may have noticed is that the order is much the same in all of these leaves, there is some 'back and forth'  in terms of approach but its broadly the same 1. underlying wash, 2. Selective colour layers into wet (2 or 3 layers)  3. Depth and Detail with dry brush on damp 4. Finishing touches and review.

Leaf 6. Two for one bonus! the front and back of a Cyclamen coum leaf. Underlying blue is the same in both. Sorry I forgot to photograph the stages of the back but it involves a lot of Quinacridone Magenta, some French Ultramarine and Permanent Carmine. The patterned front is easier than it looks: underlying blue is Cobalt and Cerulean, paint in the veins and outer edge lightly using a green mix for the veins and a yellow biased mix at the edge. French Ultramarine, Windsor Lemon and Quinacridone Magenta is used.  Add centre pattern working between the veins by wetting the area to be painted first and use a stipple effect to blend into the lighter blue area between the centre ands margin colour which has more yellow in the mix. Build colour using dry brush. Put in the flash of magenta on the central vein and petiole and it's done! 


Process of the front in stages and the latter stages of the back.

Finally, I achieved the small goal of painting a leaf every day, simply by staying up for an extra hour at night or getting up a little earlier, which felt quite satisfying. I realise now that I could do the same with other work, especially if I also neglect the food shopping and other domestic tasks.
There wasn't much left in the garden by the time I reached leaf no 7. but I was determined to finish this. I chose an ageing rose leaf, which was pretty much about to drop all its leaflets except the green one, which was clinging on for life. This explains the missing leaflet on the left hand side. An interesting one to paint because I used 3 different underlying colours, blue, violet and yellow. I decided to paint this one on Schollershammer 4G paper, which is great for crisp edges and most like the surface of vellum - but use too much water and it will look like the mountains it will cockle so much. It's a great surface if you're in training for vellum and want to work dry. Alas, its a shame that it doesn't seem to be available any more as its my favourite paper for drawing too. Such is life.

Leaf no 7 Rose. My first compound leaf. A strange looking leaf from the underlying colours,  cobalt on the green leaflet and Cobalt and Quinacridone Magenta on the brown leaflet to make violet with Windsor Yellow on the Yellow ones. I used French Ultramarine, Windsor Yellow and Permanent Rose for all colour mixes. 


Thats all folks! .......until next year.

Wishing you a great New Year with much painting in 2020



Saturday, 14 September 2019

Painting Rich Colour, Texture and Detail: Rudbeckia

This week I painted the second in a series of four illustrations, a Rudbeckia inflorescence, a cultivar called "Summerina Brown", which has dark golden brown velvety 'petals' (ray florets). This type of colour and texture can be challenging and in order to achieve such a finish it's necessary to understand two things. Firstly, the importance of underlying and interacting colours and secondly the necessary of different watercolour techniques to maintain underlying colours and build texture. Here is a little about my process.


Lighting
These flowers are incredibly obliging for the painter, they flower for months and last a long time once cut, towards the end of summer they start to yellow producing amazing autumnal colours. I began by lighting the plant to make the most of its colour, using a 5,500 k daylight lamp with a CRI (colour render index) of over 90. I wanted to bring out the full range of colours and the velvety texture, without good lighting this isn't possible, is I played with the light until I created the desired look but kept in mind the true colour of the flower at all times. I took many reference photographs in case the flower wilted, but it didn't! 

The flower: I used a few different flowers for reference, this one had a slightly gnarled centre, so I used one with a fresher looking centre. I lit the flower dramatically to bring out the golden colour and to make more of the highlights which had a contrasting violet appearance in places, these contrasting colours work to enhance each other. 
Research 
I made sketches and notes about the plant and other Rudbeckias in my garden. It's a member of Asteraceae, which have an inflorescence comprising a central disc of tiny flowers, surrounded by the petal like ray florets. In this Rudbeckia the stem is ridged and hairy, leaves are simple and hairy on both sides. I also made sketches of other Rudbeckia from the garden as seen below, but this Summerina Brown is my favourite and I loved the way the petals twist and turn, it makes a much more interesting composition than the one below, which is nice but quite stiff.

Sketchbook studies: A different Rudbeckia, gorgeous colours but not such an appealing shape.
Process 
Colour matching is the first task and I do this in good natural daylight. I identify any underlying colours, there are violets and golden yellows. and dark red/browns in the ray florets.
I begin by painting in the underlying colours in the petals, I identify rich violets mixed from Indanthrene Blue and Quinacridone Magenta and also a warmer mix of Indanthrene Blue and Permanent Carmine (mostly carmine). I also drop in a few small highlights of a lighter Manganese Blue which makes the violet pop.

Putting in the underlying colours also creates form and structure in the early stages of the painting

As a slight aside, I can't miss out the central disc structure. I plotted this by lightly drawing in the two spirals, one is clockwise and the other counterclockwise, you can probably see below that one spiral is not as steep as the other. This is actually easier than it looks if you sketch the spirals in and then paint around the little flowers, towards the centre of the disk they disappear into a furry type of appearance.  I paint the spirals in first but not as straight lines but painting around the little bumps of the flower and add a the violet wash over the top, varying the colour slightly from a blue violet to a red violet by altering the ratio of blue and red. I leave the yellow pollen areas clear of paint and add yellow later. Finally. I deepen between the flowers where necessary using creamier darker mixes, which are almost black using the same colours as the painting develops, the colours are Indanthrene Blue, Permanent Carmine and a touch of Transparent Yellow.

This is a typical composite Inflorescence. Here you can see the two spirals in the central disk, which comprises many tiny flowers, the yellow is the pollen from the open flowers at the outer edge. Flower opening is sequential and this maximises a chance of pollination over a long period. Each tiny flower can develop into a single seed if successfully pollinated. 
After painting in the underlying violet colours I start to add selective areas of the golden colour, I do this by dampening the area where I want this colour to shine through and apply by dropping a condensed creamy mix of Transparent Yellow mixed with a touch of Scarlet Lake into the brighter areas. It's important to control the intensity and spread, so dampening the area with the right amount of water is important.
I also start to add the darker reds, using a combination of 3 reds. The reds in this flower vary from cooler to warmer mixes depending on the light. The three reds used in this painting are Quinacridone Magenta (cool), Scarlet Lake (the brightest 'hot' red) and Permanent Carmine (darker warm red). I also mix very rich dark purples for the deepest shadow areas using the Carmine and Indanthrene.

Adding the bright colours, yellows and reds.
At this stage, I begin to build the petal colour and texture. Using transparent yellow, scarlet lake and Permanent Carmine in different ratios of mixes, I continue to build colour by what I refer to as 'selective application' wetting/dampening small areas with clean water  and dropping in colour. In fact I seldom add a wash of any one colour all over any subject and use this selective approach all of the the time, its more like a 'patchwork' painting.

building up the petal veins with soft veins 

As I build colour less and less water is used, ironically water can be the enemy of the watercolour botanical artist, too much in a flower like this will spread and dilute colour, it can also flatten the intensity of the colour and smother the underlying colours that we want to preserve,  making them dirty (not to mention the problem of ragged and hard edges) - too little water makes unsightly thick paint, so I find dampening the the most useful approach.
There are deep ridges and soft veins in the ray florets/ 'petals' and I dampen the area and paint these using a fairly thick mix of paint onto a pre dampened area so that lines are soft. To define edges I wet the outer edge where the hard line is needed and drop creamy paint at the edge and soften inwards. I use dry (damp brush is probably a better description) on a slightly dampened surface to create the velvety surface texture.  There is much selective layering and building of colour, some needs to be overlaid and other areas preserved - at this stage I find that I have to be brave and keep going! adding small amounts of reds, violets and brown using these techniques but still using the same colours by dampening and dry approach interchangeably to control the colour. At this stage I must keep a close eye on the light and shade in the flower to see the bumps and crevices in the 'petals' and elsewhere. I try not to make assumptions and keep looking at the subject for clues.  I find consistent lighting from a lamp and squinting helps me to see the lights and darks yet I always use a magnifier to see and paint the detail.

Bring up to this stage using the red/brown mixes for the colour building. I use dry on damp and dry on dry depending on the desired outcome, dry on damp is great for those soft veins. A wetter surface is needed for creating a sharp edges and dry on dry can create more texture.

I add the stem and this looks almost finished but I continue to add more colour as the actual flower is richer. Definition is still needed in the center and edges.  
 I add the green stem and a single leaf, for this mix I use underlying blue on the light side of the stem (Manganese Blue) and underlying violet at the shade areas (Manganese Blue and Quinacridone Magenta) these subtle colours are hardly visible but do make a difference. I use a mix of Indanthrene blue, transparent yellow and a touch of quinacridone magenta for the green mix (yes the same colours as used elsewhere) I paint in the darker ridges and than add a yellow biased green mix first, followed by a richer darker green (more blue and red in the mix) - using the same colours in the flower and the greens creates more 'unity in a painting. I never find the need to use ready made greens, some greens contain black and other pigments that flatten the colour especially when mixed. Don't get me wrong some ready mixed greens are probably ok but I never find the need for them.
Finally, I add the fine hairs at the edge that are on the white paper using a mix of manganese blue, quinacridone magenta and transparent yellow to mix a grey, where the pale hairs are on the green, I use some white gouache and add a small amount of the same colour. I also paint a small shadow line under some of the hairs using a violet mix. At this point I put the panting away for a day and then review.


Rudbeckia watercolour size 28 x 18 cm The finished painting, slightly deeper colour  added all over.


Materials 
Paints, Windsor & Newton artist quality: 
Reds: Quinacridone Magenta, Scarlet Lake and Permanent Carmine
Yellows: Transparent Yellow 
Blues: Manganese Blue and Indanthrene Blue 

Brushes:
Winsor and Newton series 7 Miniature size 4 and 2 

Paper:
Saunders Waterford  140lb (300gsm) HP  High white 

I've been using this paper for all my tutorials and paintings over the last few months and find that it's pretty robust. so for the moment will stick with it.  I seldom need a heavier paper as I don't use much water, I only use heavier paper if working on large paintings, such a a full imperial sheet size. 















Saturday, 24 August 2019

Beginning in Botanical Art and illustration

I saw a post on social media the other day from someone asking about where to start in Botanical Art and Illustration, it got me thinking about the important points. So here's my not so short take on the subject based on my own process, where I started and what I needed to learn. I've made a top 12, there's probably more. These are not intended to be rules and of course there are many different learning styles and approaches .... this is mine.


A foxglove, Digitalis purpurea from my sketchbook, it doesn't have to be finished - it's a place for working things out  rather than perfect illustrations
First of all there is no magic or quick route, it will be hard work at times and requires tenacity. Outcomes may be frustrating at times but it will also be fulfilling and will make you so happy when you succeed, you will love it and your obsession with plants will grow.... but  be aware that it will be a rollercoaster! There is nothing more exciting than a new subject and a blank sheet of paper. So here goes:

1. Study a little botanical art past and present: from the old masters and contemporary artists, this will feed your mind. Look at the big names Redoute, Ehret the Bauer Brothers and Sydney Parkinson, etc.  alongside the more recent greats such as Rory McEwen and Pandora Sellars and right up to date - there are a huge number to choose from, so I won't name any contemporaries but there's a great library of images online these days. When I say study,  I mean really study them - buy a little notebook and make a list of the artists you like and ask yourself what it is that you like. Don't just be overawed at the impact of a beautiful work but look a the the finer points, such as the light and shade, learn to see where the light is coming from and how the artist used it. Look at how the the colours are handled and the composition. Also maybe look at work that you don't like so much and ask yourself why? You don't have to buy books but there are a few that are useful, lots of resources are available but also try to visit exhibitions - there is nothing quite like seeing the real thing!

Sketchbooks of George Ehret (1708 - 17700 at the Natural History Museum

2. Keep a Sketchbook: this is a must do! This keeps everything in one place and you can see your progress over time. It's your place and you don't have to share it unless you want to. Start with simple subjects drawing first, then gradually introduce tone by shading and colour by making simple colour swatches to match the plant at first. Finally, work out the process for painting. Make notes on everything,  name, the date, write about features of the plant.....this will improve both your observation and knowledge of plants. It will build a wonderful reference library! Leave in the stuff that went wrong too, its a lesson in itself! but if you really can't stand to looking at your mistakes simply stick something over it.
I use the Stillman and Birn Zeta series soft back because it has a heavyweight paper at 270gms and handles washes well, I occasionally use the Epsilon series for graphite work as the paper isn't so heavy and isn't needed for graphite. I don't much like ring bound books because I like to work across double page spreads (as you can see). It's available in a range of sizes,  I use the 8 x 10 inch (20.3 x 25.4 cm) book, any larger becomes too daunting and not so useful as a sketchbook because it's too big! but also the 5.5 x 8.5 inch (14 x 21.6cm) are good, and the mini book 3.5 x 5.5 (8.9 x 14cm) is great for keeping in your bag! see their website for sizes www.stillmanandbirn.com
Keep in mind that sketchbook paper isn't ever quite up to the standard of watercolour paper so it will handle slightly differently than a cotton paper. You can make your own sketchbook of course but thats another subject.

The 8.5 x 5.5 inch still man and Birn Zeta series book on the left and the mini 
3. Draw from life and do a little everyday: That means observational drawing from an actual subject, which is important because you can see how a plant is constructed, you can turn it around, hold it in your hand and get a feel for it's texture and surface and you can even take a plant apart in order to understand it. You just can't get this from photographs, I'll write more about using photographs later but they are flat 2 dimensional images and can distort shape and colour and you often can't understand the growth habit of a plant if you are not familiar with it.
I start with the most basic measurements, height and width of the whole, then break it into parts. Look for shapes within the subjects, circles, and triangles, look at angles.
Don't be afraid to correct or to try again. Drawing is a process of working it out, don't expect it to be correct from the start.  Start with simple obliging subjects: no one wants to see droopy leaves, choose tough flowers, long lasting buds, fruit and seed pods. Avoid subjects that move with the light or wilt. Make sure that you align parts correctly in your drawing, especially where a stem passes behind other part and re-emerges or  where the stem lines up with the flower centre, it's all connected from the stem to the ovary. Remember that the seemingly complex web of veins in a leaf meet up, all of these things can be broken down into an order ....misalignment is one of the main errors in drawing, so check overtime. Create a check list to ask yourself questions for every drawing and be your own critic.
Deconstructing a Hellebore
Hellebore: Graphite Sketchbook Studies using line and tone as preparatory work for a larger study. Notice all the measurements and enlarged parts. Enlarge by multiplying the measurements for parts that are too small to easily see. 
Always sharpen pencils and understand their tonal values from H (Hard grades) which are the lightest in tone to B  (Bold)  which are the softest and darkest. 
4. Research your subjects: Being a botanical artist involves detective work! This is your plant research and it goes hand-in-hand with numbers 2 and 3. I put my research notes into my sketchbook. First of all find out what are you painting, i.e. the plant name, you can use flora books or online resources for this, but if you don't know exactly what it is say so and don't guess. It's much easier with species than with cultivated plants. If you buy a plant be sure it has a label or ask the name and check that its correct, you can often find a description in a book of  for name and also what family the plant belongs to. Learn a little about the system of the Latin or scientific name (the 'two name' binomial system)

For example 'Foxglove' is a common or vernacular name.
The Latin name is Digitalis purpurea which is written in italics or if hand written is underlined.
Digitalis is the first part of the name, this is the genus
The second part of the name is  purpurea, this is the species or specific epithet.
A quick Google search also gives the family name Plantaginaceae, this is not written in italics, it's always worth learning which family a plant is in because you find out about relationships and similarities and differences in families.
This system may seem complicated at first but the 2 name system, known as binomial nomenclature, was largely developed by Carl Linneaus in 1753 and it's used to name all living organisms and is the  internationally recognised system, so we need to know about it  - in actual fact it avoids any confusion. It's really not that difficult if you don't try to learn too much at once, deal with it on a plant by plant basis.  Then there are hybrids and cultivars derived from those species but I'm not going to go into this here.

Next: describe your subject, you don't need to be a botanist simply describe in your own words initially, a book like the Cambridge Illustrated Glossary of Botanical Terms by Hickey and King is a good reference. For example descibe the shape of the leaf, whether it's hairy, it's outer margin, the pattern of the veins, the shape of the flower, the shape of the stem and reproductive parts etc. gather as much as you can. This sounds like a lot but if you sit down with a plant you can describe it in about half an hour and it's well worth the effort.
Plant research, name and describe the plant, its parts as well as the process
5. Choosing and keeping subjects: Don't pick overly difficult subjects in the beginning it can be the most frustrating experience for a beginner ! Go for more robust plants, orchids are obliging and fruits are fantastic subjects! they last for a long time and change slowly. Start smallish but not too small that its hard to see or draw. Seed pods and dried subjects make great subjects too and can be kept for a long time, so start collecting! dried leaves, nuts twigs and seedpods. Pot plants are very handy as are the contents of the fridge, chili peppers, garlic, vegetables etc. With plant cuttings, keep them cool when not in use, either outside or if it's hot or in the fridge in plastic containers on damp kitchen towel. If flowers wilt, cut the stem and plunge into hot then cold water to revive.
Seedpods are very obliging subjects for a beginner
 
Something from the fridge! There's always a treasure trove of subjects 

6. Know your materials: Its' all too easy to get carried away buying materials and equipment that you don't need, based on recommendations but this is often a form of procrastination. While it's nice to have a every colour in the shop - you have to ask yourself if you need all of these paints? will they make you a better artist? The simple answer is no, while it's important to have good quality paints, brushes ands paper - you don't actually need all that many paints. I work with a primary palette of 5 reds, 5 blues and 4 yellows, you can read about that in my last post. There really is no need for anything else. It's more important that you learn what your colours are, understand their properties and know how to mix them. Again, refer to the previous post.
I mostly use two brushes, a size 4 and size 2 series 7 Winsor and Newton miniature, plus a synthetic filbert size 1, and a flat, such as the Rosemary and Co eradicator to the Pro Arte Masterstroke flat shader, they cost less than £3. I also have a size 6 flat for mixing and taking paint out and a basic sable wash brush size 6.
Paper is a matter of choice so try sample packs, you need to actually paint a whole subject though to really find out if you like it or not. It's a good idea to exchange paper samples with friends rather than buying expensive paper that you don't like. But you will need a Hot Press (HP) paper, because it has the smoothest surface for fine detail, some artists paint on Cold Press but this has too much texture for me.  I use a few different papers mostly 140lb (300gms) all are 100% cotton. For example: Saunders Waterford HP ehigh white, Arches HP and Stonehenge Aqua. Only use heavier paper if you're working larger or paint with a very wet style.
A good quality range of pencils, such as Faber Castell 9000 grades 4H to 6B
A putty eraser and hard dust free eraser, a retractable Tombow eraser too
You will also need a couple of ceramic palettes, ceramic is better than plastic
Something to measure parts with such as a transparent ruler and/or dividers
Magnifying glass x2
My paintbox and an exercise matching colours using the primary palette of reds, blues and yellows

My trusty old paintbox. I use a ceramic palette with wells (shown here) for watery washes and a flat palette for creamy and dry mixes. 

Flat ceramic palette for thicker creamier mixes and dry brush 

7. Make the workplace comfortable with the correct equipment: If you're not comfortable, you can't paint well, it sounds silly but makes sure that you can reach your paints and water and that they are on the correct side, thats the right side for right-handers and the opposite for left. I can't tell you the amount of times I've seen students trailing a wet brush from the other side and then wondering why they have so many splashes on their work!
Invest in an adjustable height chair - it's important not to strain your neck and to be able to get at the parts you are painting.
A drawing board, which can be elevated is useful, a piece of MDF and a block of wood will do. Elevating the drawing board means that you can see what you are doing properly, a board laid flat creates perspective distortion unless the subject is small,  this perspective issue occurs because the top of the board is further away than the bottom of the board.
I use a lamp for painting with a daylight bulb (there's a post about what a daylight bulb is somewhere in this blog) and a lamp on my subject. The lamp on the subject is generally pointed at the subject from the upper left if you are right handed, and the upper right if you are left handed.


8. Understanding the tonal values to create realistic form: can you see the light?
I mentioned having a lamp positioned on the subject in 7, this is vital to create constant light and shade and to make an interesting drawing or panting with good form. While natural light is great, it does change throughout the day and this can confusing for beginners. Light and shade is important in our work, so its worth spending some time on it.

Start with rounded forms, these are the easiest, and work up to more complex ones. Use photography to turn images to black and white as this can be very useful to see the lightest and darkest parts and all of the areas in between.

Light coming from the upper front left side on this apple, means that the shade is on the right but it's also got some  light reflecting back onto its shiny surface beneath the form shadow. Light and shade can be confusing we have to train ourselves to use it 


Tonal painting and contour drawing of an apple, showing the light coming from the upper right this time.  Note where the highlight is and the form shadow, everything in between are mid tones, if light is too diffused there isn't enough light and shade to make and interesting painting or drawing, so play with the lighting.

Always sharpen pencils and understand their tonal values from H (Hard grades) which are the lightest in tone to B  (Bold)  are the softest and darkest. Start light and work towards the darker shades.
To make tonal studies you can use pencils, black paint or a neutral tint mix, it's a good idea to get and overall feel for a subject by making a tonal study first, this will ensure that you get the tonal values right.
Heres a measured line drawing of a leaf and a tonal study of the the same leaf using continuous tone.  See how light and shade is used to create form. The shading involved starting with a 2H and building up to the darkest tones with HB, 2B and 4 B
Converting this concept to colour can be more challenging but if you understand the basics of light and shade first it will be much easier to create a convincing looking painting.

Initial tonal drawing for the painting below. it's important to understand the different tones between parts and  in relation to light and shade, the light flowers will require harder grades of pencil and the darker leaves will require softer grades. The more shaded areas also require softer grades. For example flowers might require a 4H for the lighter parts but no harder than HB for the darkest areas within them, whereas leaves might start with a 2H for the lightest parts and working up to a 6B for the very darkest parts, using every other grade in between.

The final painting maintains the same tonal values. Convert your image to black and white to check them! 

Photographing and converting the colour image back to black and white helps me to check those tonal values. 

9. Learn Techniques in graphite and watercolour: Spend time experimenting with techniques. With graphite we mostly use the continuous tone technique, this produces a smooth finish, the motion requires elliptical movements, working over and over lightly to gently work the graphite into the surface of the paper, other techniques include stipple and hatching. I can't cover all of these here but if you delve back in time there are some posts on shading in graphite.
With watercolour you need to be able to use flat washes, graded washes (from dark to light), blended washes (working from one colour into another), wet-in-wet (dropping colours into a wet surface and  controlling them) but to really achieve the depth and details in nature, the dry brush techniques are necessary too. There are  a number of approaches to dry brush, which can be used to model the surface of a subject building rich colour, or to add different types of detail, the approaches are different and I use 5 different ones.  There isn't room to explain all of these here but i'll write more in the future. Take a class if you can but make sure it's one where you will learn these techniques and methods. Once you have the techniques learned you can really start to develop your work, you can make clean edges, rich colour, texture and fine detail. All of which are vital for botanical artists.

Learn the various dry brush and wash techniques. From my watercolour Techniques Tutorial, modelling dry brush
10. Learn about colour mixing: This relates back to the previous materials entry. Learn about primary palette colour mixing, make colour charts  and experiment with saturated and desaturated colours. Practice matching colours to a subject.  For example, if you have a red / orange flower, start with the nearest red in the palette, if the flower is leaning towards orange, add some yellow to it, if it's leaning towards purple add blue. That's a simple version but if you use a limited palette you soon get to grips with the warmer and cooler versions of colours in your subjects.  Colour charts and wheels can really help with deciding where to start and you can simply place your flower on them to see what the nearest colour is. Greens need special attention, you can read previous posts on green mixing but bear in mind that most greens will require a blue plus a yellow and then a very small amount of red to make a more natural green, again,  if your colour palette is only primaries this makes it quite easy. Simpler principles can apply: for light greens use a light blue, for mid greens use a mid blue and for dark greens use a dark blue. This sounds obvious but it's often missed.
Purple chart, mixing and matching purples to the subject using the blues and reds
11. Draft and redraft: After making sketches and deciding to compose a painting, draft out a rough composition, this can be done on tracing paper. Re-work the drawing until you are happy with it, arranging or rearranging. This preparation work is preferable to rushing in with a painting and eliminates the possibility of errors.
Drafting the layout for a composition using tracing paper, parts are cut out and rearranged slightly. 

12: Photographs: Don't be afraid to use technology. Photographs can be useful to supplement your work but it's important to understand the subject first and to be able to draw it from life but don't ever rely on photographs for colour as they can be quite inaccurate.
You have seen that in this post that I have used photographs to check for tonal values and to check and play with lighting effects. Photographs are also useful  for capturing subjects in the field and that change or are short lived.
Equipment like light pads are useful for transferring drawings. Digital microscopes are amazing for close-ups of small parts and apps can even be used to edit images of your work to see how they might look with more colour or darker tones. Technology isn't something to be afraid of, it's just another tool.

Most of these points can be expanded on, this post is intended to provide an overview of some of the processes involved in producing botanical work. Hopefully I will be able to expend on some of them in the future.