Backruns, blooms and cauliflowers
Blooms in watercolor occur when a drop of paint or water is placed in an almost dry paint surface. The added water lifts the almost dry color and pushes the pigments towards the edges. When the moisture is no longer able to move, the pigment collects in a special pattern that characterizes blooms. Due to their shape, these patterns are often called cauliflower, another name is backruns.
Many years ago, I thought that blooms characterize a watercolor painter who does not master watercolor techniques. That only amateurs allowed backruns to occur. It even happened that I discarded a painting where a backrun had occurred. Nowadays I have a more forgiving attitude: Blooms happens and sometimes it can even be nice. So when it blooms in a painting, I let it be, even though it’s usually not something I strive for.
Characteristic of blooms is that they can occur spontaneously but are difficult to achieve planned. I do not know why, but I find it difficult to get color to bloom on command. When I make the color samples for the texts about different watercolors, a sample of the backrun is included, it does not always work to make the color bloom when I paint these samples. But in a painting where I do not strive for blooms, they appear all by themselves.
Different colors bloom differently, it is mainly colors of pigments that are light (moves well in water) and that are colorful and transparent that like to bloom. Examples of such colors are different phthalo and quinacridone colors and Prussian blue.
If you want to achieve backruns, you should avoid opaque paints, granulating paints (heavier pigments) and very light colors, examples are: Ultramarine, cadmium paints and cobalt paints. Such colors do not bloom very well. The paper also plays a role in a color’s ability to create backruns, a good paper does not create backruns as easily as a bad one, the simpler watercolor paper the easier it is to create backruns.
Some artists strive for blooms while others try to avoid them. An artist who is especially worth mentioning in this context is Carol Carter, she uses blooms in a constructive way, take a look at her paintings of plants, they are amazing.
In modern watercolor painting, blooms occur from time to time, but almost never in classical painting. So the attitude to the phenomenon has changed over time. What was once largely banned is now widely accepted and is even something that some artists use as an artistic element in their paintings.