Vallejo Model Washes are supplied in 35ml bottles with a flip-top lid. They have been formulated with a modified acrylic resin so that the surface tension is similar to that of the traditional solvent-based washes and filters, but with the advantage of working with a water-based (and less smelly !) medium. Average drying time is around 20 minutes. If several layers of wash are to be applied, it is best to wait around 40 minutes between applications. They can be applied by brush or airbrush, and painting tools are cleaned with water.

These washes have the effect of blending the edges of the colors on models painted in camouflage shades, and creating a generally lifelike weathered appearance. The colors can also be mixed together to achieve further variations of shade and can be used with airbrush or brush, according to the model and the effect desired. Model Wash can be mixed with pigments to achieve a wide range of effects such as oil and flaked rust, mud, earth, dust, moss, etc. and when mixed with acrylic colors, they further help achieve the look of heavy wear and weathering.