Letting the Paint Do What it Does
Water colour painting can be a challenge. A lot of artists avoid it as it tends to do what it will on the paper. Interestingly, you can have control over your water coloours depending on how you use them, and really, some of the beautiful affects gained when allowing the paint and water to flow and merge can be a delightful happy accident or surprise.
Wet in wet is a technique that applies to the idea of allowing the paint to flow and merge. How much control you want to attempt over this is up to you.
Some artists completely soak their paper , or alternatively, you may like to tape down your paper and wet only certain areas of the paper to restrict your wet in wet affect. How you gain some control over this mixing and blending as the paint moves on the surface, is partly determined by the angle you have the paper on. Of course, laying it flat will stop a lot of running, but as you increase the angle towards an upright position, the paint will run more quickly. You can also tilt the paper in different directions to see what sort of results you get by changing the direction of the flow.
Keep in mind that various papers will handle being wet differently. Some will buckle more than others, so will need to be taped down all around the edges after being soaked.
Another method of controlling where your paint goes is to apply masking fluid to the paper while it is still dry. You can then wet it, and paint in your colours. When dry remove the masking fluid and continue painting.
Wet in wet give you a beautiful soft blend of colours. Some mixes will separate a bit as they flow down a textured paper, with pigment settling into the lowest points on the paper’s surface. It is great for painting skies, especially sunsets, and is also very good for painting water like the sea or rivers. You may like to try mixing your colours then dropping them on to the paper, or adding a couple of pure colours to see how they react to each other on the surface. Just keep in mind your colour theory when painting like this, as keeping a ‘base colour’ or tone will help to keep your painting looking unified, and the colours relating to each other. If you are using cool colours, restrict how much warmth you add as highlights for example.
For further information about wet in wet see the link below.