Blending Gouache Gradients
This demonstration is to show the technique I use to blend a gradient of different colors of gouache together. For this project Iíve chosen three premixed tube colors of Titanium White, Cadmium Yellow Lemon, and Burnt Sienna (DaVinci brand.) The painted surface is on illustration board @ 5x4 inches square. Iíve used this same technique for casein and acrylics, even oils. Each of these paints has their own characteristics, but the blending principle is the same.
Brushes: medium sized sable #8, 1Ē blending brush and/or fan brush
Small mixing dish or palette
2 water cups: dirty water for cleaning brushes, clean water for thinning paint and blending
In this example Iím using colors straight from the tube to speed up the demo. If you want to mix two colors like white and black, you should make your own gray from them, rather than blending from white to black on your surface. The idea is to mix up the values ahead of time on your palette (dish in my case) to facilitate the blending. You shouldnít need to make more than a couple values in either direction. This procedure requires a good bit of paint, so donít be stingy, baby
Prepare the surface:
Slightly dampen the paper surface with a sponge. It gives you a more receptive surface to work on. If youíre going to be working on a previously painted surface, be careful with the water, or you may want to use a brush, but donít get the surface too wet. I also like to slightly dampen the brush before start to help it flow better, but, again, damp not wet.
Lay down the middle value first as your target range. In this case thatís the yellow. Place an even band of paint across the area in a consistent volume. Clean your brush completely (tip: if you have more than one brush, that can be convenient here.) Lay down a band of brown, and another of white, cleaning your brush between each application.
Mix up the in-between values of paint; yellow to white, brown to yellow. Apply bands of paint for those values on the paper. If youíve got a large area to blend you may want to mix up an extra value range, for instance, white-white-yellow and yellow-yellow-brown.
With a clean brush, start blending. I start with short ďxĒ marks along the bands, constantly wiping the brush as I go from one band to the next, and sometimes adding more paint. The last step here is to brush it in smoothly with a large blending brush or fan brush. Sometimes I prefer a more ďbrushyĒ texture, and donít smooth it out. This final brushing also removes a bit of paint, which can cause a problem with irregular volumes of paint. Be prepared to go back over certain bands with more paint to blend them more evenly. This will require more pre-mixing.
I canít emphasize enough the importance of a clean brush as youíre moving from one value range to another. If youíre using a blending brush, when brushing perpendicular to the values (light-to-dark,) clean it after you make each stroke. When brushing parallel, clean before you move to a new value range.
Some colors cover better than others (transparency/opacity) and this affects how they blend. More transparent colors can require more volume of paint, but less so if painting over thin washes of more opaque colors. Mixing the value range ahead of time makes blending them easier.
Go easy on the water use. Donít blend the paint in water, blend paint in paint. The only water used in this demo was the tiny bit left on the cleaned brush and the slightly dampened paper. If the paint dries on my palette, I wet it by adding paint, not water.