There are several ways to make acrylic paint flow better, which is the process of making it thinner. The three most common ways are: - Diluting with water - Diluting with medium acrylic gels - Diluting with other acrylic paints and mediums. Water works well, but it affects the color of the paint. Adding other acrylic paints does not work well. Medium acrylic gels do work well, but they are not so good for the environment. They also tint the color of the paint a little.