Working with acrylic paint has to be fast, as the paint dries in about 20 minutes. The advantage of time constraints is that brushwork is immediate; however, because of the nature of acrylic paint, over painting can easily cover changes. Because this paint is plastic, in all cases the paint needs to be mixed with acrylic gel/ either matte or glossy and may also be thinned down with water to be used as a glaze. Mixed with a heavy acrylic medium, the paint can appear to sit in the clear gel. This heavier gel also allows other materials to be added to the picture: grit, textiles, extra canvas pieces. This is what I mean in most cases when I refer to “mixed mediums”.
Watercolors make immediate marks and stains on paper. With the same brush they can be used sparingly (wet into dry) for tight control or saturated (wet into wet) with more loose (wash) result. I usually use watercolor paints in the summer – when it’s easy to work for a while and break for a walk on the ocean. I leave paints, palette & paper out and not worry about paints drying up. (They do anyway.) Clean-up can come at the end of the day. A big (mop, grey squirrel hair) brush can be full of watercolor paint and used lightly to make a thin line or heavily to create a wash of color. For me, it feels like carving with a painted line.