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Thumbnail Sketches


There is nothing worse than launching into a large sheet of watercolor paper and, after five minutes of confidence and enthusiasm, discovering there is a big dark, composition destroying shape right in the middle of the painting.

Example of two simple, pencil thumbnail sketches
Sketch demonstrating the importance of correctly proportioning your thumbnail sketches.



To avoid this situation is simple – before launching into your large sheet of paper, spend a couple of minutes roughing out some thumbnail sketches.


Thumbnail sketches only need to be the size of a credit card and require no detail, simply arrangements of shapes and tones. If you spend more than a couple of minutes on each one you are probably being too detailed. Any scrap of paper will do and a soft, 4B – 6B pencil will make nice dark marks.

The idea is to mass areas of similar tone together then arrange these massed shapes to form an interesting composition. Work out what will be your focal point, place it in a suitable position (generally not midway either vertically or horizontally) then make sure the darkest dark and lightest light occur at this point. Use the other shapes to lead in to and balance the focal point.


This process may take a couple of sketches but, once worked out, it provides a good solid foundation for your painting.


For your thumbnail sketch to be effective it is important to make it the same proportion as the paper or canvas you will be painting on.

Four thumbnail sketches showing how tonal rearrangement can be tested before painting


These four thumbnail sketches show how various tonal arrangements can be assessed before picking up a brush. The subject is reduced to three tonal groups – black, grey and white. Although the sketches are small and rough, the different atmosphere created by the various tonal arrangements can be clearly seen

Example of thumbnail sketch and resultant watercolor painting.


Sometimes a single thumbnail sketch is enough. In this case redrawing the boundary line showed what it would be like to push the subject into the upper third of the painting rather than sit it in the lower third.

Colored thumbnail sketches


Thumbnail sketches can be used to compare color options too. The first sketch should get your composition and tonal arrangement sorted out, then using that composition, try out a few different color options.

Example of tonal and color thumbnail sketches



Adjusting the composition is done with the thumbnail sketch, then another small color thumbnail establishes the color arrangement.


With the knowledge you gain from a few thumbnail sketches you can attack the painting with much more confidence. It is the strength of the composition that makes or breaks a painting not accuracy, detail or technique. Having a good solid plan to base your work on frees you up to run risks and experiment.




Occasionally more detail in thumbnail sketches helps resolve problems with a difficult subject. These multi layered paintings of leaves and sticks are produced by painting the negative shapes. Pushing the composition around with a reasonably detailed thumbnail sketch helps get your brain adjusted to the technique before starting to paint.

Detailed pencil sketches


Sometimes a thumbnail sketch can be used to clarify and edit the subject. These little sketches with scribbled notes are to remind me of adjustments made to shapes, colors and details. They are used in combination with a small rough compositional thumbnail sketch.


It may seem like an unnecessary waste of time – scribbling little sketches on scraps of paper before you start to paint. However, five minutes sorting out a thumbnail sketch can save hours of toil and heartache when all your efforts go into a badly composed painting.


The final important point is to make sure you refer to your thumbnail sketch, not your source material, when you start to sketch out your painting. Be as faithful as possible to your thumbnail sketch and transfer it to your painting surface as economically as possible.


The time to refer back to your source material is when you start to build up detail once the structure of the work is in place.


So before you launch into your next painting put aside five minutes the shuffle around a couple of thumbnail sketches. Having even a very rough plan makes the painting process so much easier.

Thumbnail Sketches – Summary

  • Make thumbnail sketches quick and simple

  • Keep the thumbnail sketch proportions the same as your finished work

  • Mass shapes into simple tonal areas

  • Establish a focal point and arrange for maximum contrast there

  • Avoid too much detail

  • Refer to the sketch, not your source material, when laying out the painting

Author: John Lovett

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