Acrylic mediums are added to acrylic paint to change its character or behaviour during the painting process.
A gloss medium is used to increase transparency, sheen, and luminosity while a matte medium is used to reduce sheen and make colours look flat. A glazing medium, which reduces opacity and increases transparency, is suitable for glazing and layering techniques. Gel mediums are used to increase body and make the paint retain brush strokes. Modelling paste works in the same way as gel mediums but is thicker and can be used to create a 3D finish.
Texture mediums change the surface appearance of paint by imitating ceramic stucco, sand, glass bead, and more. Airbrush mediums, apart from being used for airbrushing technique, can be a good painting tool to dilute paint to a fluid consistency or create watercolour-like washes.