A tonal sketch is an ideal method of working out your composition and also where the lights and darks are going to be placed in your picture, regardless of what colours are involved.
Look at this example of a picture I produced a while back...
It's the delightful village of Wrea Green about 45 minutes from my home in Liverpool. It has everything the 'typical' English village should have - an ancient church, a pub and attractive cottages and houses surrounding the village green, complete with its duck pond.
When Pam and I visited, we noticed that the green had a cricket pitch marked out, so this seemed the ideal solution of creating human activity to link all of the elements together in a picture.
Always look out for a chance to include animals or people in a meaningful way when considering your composition. It could be a couple walking down a lane or someone on a horse, or even a cluster of hens near a farm gateway.
Anyway I digress. I made three tonal sketches of the scene, using a 4B pencil on a cartridge/drawing paper pad.
Each view was changed slightly to try out different angles and arrive at the best composition.
In Picture 1 above I felt the buildings had become too far away and 'bitty' and the cricketers dominated rather than complemented the scene. So I changed it...
In Picture 2, I made the figures smaller, but the church was placed too centrally for my liking.
I have a compositional dislike of any significant element placed right in the middle of a picture as it can tend to cut it in two. Equally, I thought putting the pond right across the bottom of the picture created an unwanted barrier - even though in real life it would be in that position.
So I had another go...
In Picture 3, I moved the view so the church was at the right hand side.
It's still towering over the village (as it does), but it allowed me to develop an 'L- Shaped' composition in conjunction with the other buildings using the height of the steeple.
I included just a corner of the pond and a couple on a bench watching the game to fill in an otherwise blank area.
Of course, a tonal sketch isn't just for establishing the best composition.
As the name suggests it helps you to figure out the balance of tones or values (lights and darks) throughout the image. Actually "value sketch" would be a better a more accurate name but that's one for another time.
Good use of value is one of the most important characteristics in any strong-looking piece of art. Poor use of value is present in nearly all weak-looking art.
Value is an easy concept to understand but one that takes a bit of practice to really master on a practical level. That's why we created our free ebook - The Number 1 Way to Improve Your Artwork.
As you can see in the sketch below I developed the light and dark areas so that when I came to paint this scene, I'd know what strength of paint to use. Colour is irrelevant remember, it's the relative lightness or darkness of your colours that will give your painting punch and depth.
The tonal sketch also allows you to 'play' with light and shade. A dark roof in reality might look much better left quite light in your picture. Or maybe you could have the sun coming from a different direction.
In Picture 4 below you can see the final painting, slightly adapted from the third sketch. I made the bench and spectators smaller as it suited the overall composition.
There are elements in your reference material you will almost certainly want to move or leave out altogether - an unwanted lamp-post perhaps. Another reason for creating a quick thumbnail sketch first.
Try producing some simple tonal sketches the next time you do a painting - in any medium.
Don't dive in and paint the first view you see. You will almost certainly get a better composition with this little bit of pre-planning.
In fact, most professional artists will tell you that for them, a tonal sketch (or several of them) is an absolute pre-requisite before they commit paint to paper or canvas.
They don't have to be a masterpiece. They're just working drawings often on scraps of paper. But they are a vital stage in organising in your mind the layout of your picture before you pick your brush up.
As an added bonus, you frequently find that your tonal sketches highlight more than one potential painting of the same scene - with very little extra effort!