Acrylic artists’ paints may be thinned with water or acrylic medium and used as washes in the manner of watercolor paints, but unlike watercolor the washes are not rehydratable once dry. For this reason, acrylics do not lend themselves to the color lifting techniques of gum arabic-based watercolor paints. Instead, the paint is applied in layers, sometimes diluting with water or acrylic medium to allow layers underneath to partially show through. Using an acrylic medium gives the paint more of a rich and glossy appearance, whereas using water makes the paint look more like watercolor and have a matte finish.
Fluorescent acrylic paints lit by UV light. Paintings by Beo Beyond.
Acrylic paints with gloss or matte finishes are common, although a satin (semi-matte) sheen is most common. Some brands exhibit a range of finishes (e.g. heavy-body paints from Golden, Liquitex, Winsor & Newton and Daler-Rowney); Politec acrylics are fully matte. As with oils, pigment amounts and particle size or shape can affect the paint sheen. Matting agents can also be added during manufacture to dull the finish. If desired, the artist can mix different media with their paints and use topcoats or varnishes to alter or unify sheen.
When dry, acrylic paint is generally non-removable from a solid surface if it adheres to the surface. Water or mild solvents do not re-solubilize it, although isopropyl alcohol can lift some fresh paint films off. Toluene and acetone can remove paint films, but they do not lift paint stains very well and are not selective. The use of a solvent to remove paint may result in removal of all of the paint layers (acrylic gesso, et cetera). Oils and warm, soapy water can remove acrylic paint from skin. Acrylic paint can be removed from non-porous plastic surfaces, such as miniatures or models using certain cleaning products such as Dettol (containing chloroxylenol 4.8% v/w).
An acrylic sizing should be used to prime canvas in preparation for painting with acrylic paints, to prevent Support Induced Discoloration (SID). Acrylic paint contains surfactants that can pull up discoloration from a raw canvas, especially in transparent glazed or translucent gelled areas. Gesso alone will not stop SID; a sizing must be applied before using a gesso.
The viscosity of acrylic can be successfully reduced by using suitable extenders that maintain the integrity of the paint film. There are retarders to slow drying and extend workability time, and flow releases to increase color-blending ability.