In classical modern watercolour painting, there are guiding rules and techniques that apply. For instance, if you wish to put on a flat wash on your paper which of course you must have stretched, here is what to do: You have to mix the colour you want to lay on making sure you mix it in double quantity before starting out. You have to double the quantity you need because once you begin, you will not be able to stop to mix up another more quantity of paint.
Illustration of washes by Marion Boddy-Evans
Once you are set, make sure your painting (board) surface is tilted up just a bit, and begin by using your largest painting brush. But note that if you want to lay an even wash to your paper or any particular area of the paper, you should firstly dampen the area with water using a large brush or sponge. And so you can decide to lay an even wash or a graded wash. Now, load your brush and gently lay it on - sweeping from the top left of the paper i.e. assuming that you are right handed like me, towards the right and also downwards.
You are to apply the paint in wide wet horizontal strokes. If you need to reload your brush that is, if it has been exhausted before the end of the stroke or band, then quickly refill your brush making sure it blends with the former one. The next band or stroke should commence quickly before the last one has had a chance to dry at its bottom end. The stroke should as much as possible catch up and blend smoothly with the last one.
When doing this kind of wash, make sure you are not tempted to rinse your brush out until the wash is successfully completed because extra water will only dilute the colour unevenly. Also, your palette or saucer of paint should be stirred each time you reload your brush to make sure sediments of pigments do not collect.
In the process of laying up the wash blemishes may still occur because it is not really easy to lay a complete wash without error and it is not very possible to retouch a wash (with success), but the secret is always to work fast and smoothly.
But if your aim is to achieve a very dense flat background of colour, then you may be advised to work on a manufactured coloured or tinted paper.
By Morgan Nwanguma