The basic principles here are: wet-on-wet is good when you need two colors to blend into each other and need the edges to be soft on both. An example of this is shading/highlighting. In this instance, we’re going to have different colors next to each other, but since we’re not actually dealing with separate objects, we want our edges to be soft, and painting with the layers still wet gives us that.
So, you might have already guessed, but if you need a sharp distinction between one color or shade and the next, i.e., if those colors represent different objects, you will want to use the wet-on-dry technique. This will create a harsher edge and thus a more precise distinction between the objects. For example, I wanted the nose here to stand out from the rest of the dog’s face, so I painted over it when the layer underneath was dry to make that separation.
I know I said we use wet-on-wet for shading, but that depends. For smooth shading, such as this dog here, on even a person’s face who has smooth skin, yes, use wet-on-wet. But for things like deep folds in clothes, or wrinkles in a person’s skin, since these things require harsher separation from their surroundings, in those cases, we use the wet-on-dry technique for part of them. Even in these cases, though, you’ll probably need to have a little area surrounding the harsher lines that’s more blended for your wrinkles to look realistic. As you’re working, you’ll probably start to see what technique works best for what you want to accomplish with the particular part of the piece you’re working on.
Okay, so that’s pretty simple. But working wet on wet can pose a problem. As you’ve heard me say before, watercolor goes where the water goes. That means, if you’re not careful, you can have paint go all over the place when trying to utilize this technique and that’s usually not what you want.
I’ve been watching another artist named Sayanti Chadhauri. She has a youtube channel called Sayanti Fine Arts. Anyway, I was first inspired to explore the possibilities of what could be done with wet-on-wet when watching her videos. Sayanti uses this technique with remarkable precision. I asked her how she paints wet-on-wet without the paint going all over the place and I’m going to share on of the things she told me with you, and that’s to avoid pools of water on your paper. That is, keep your water layer relatively thin. Believe me; this has made all the difference. Since I started paying attention to how much water I’m putting down, my layers have been much more controllable. So wipe your brush on the edge of your water container and even dab it on a paper towel if you have to, before putting it to your paper.
Don't stress out too much about which technique to use. You're going to misjudge sometimes. Use your eyes. If you use wet on dry and the edge is too harsh, soften it with a wet brush. This is easy to do while the paint is still wet. If you use wet on wet and the result is too fuzzy, dab it with a tissue and start over.
Painter of portraits and wildlife