This medium is a heavy-bodied paint, free of colour pigmentation (it isn't a gel).It is most valuable for oil painting brush stroke and impasto techniques, particularly when heavy built-up areas of colour are required.Impasto Medium dries to a low subdued sheen which is similar to the sheen on a dried paint film of acrylic colour.It is equally water-resistant.Impasto Medium allows for free intermixing with the Derivan colours in any proportion. There is little visual colour loss when equal volumes of a Derivan colour and Impasto Medium are intermixed. Although Impasto Medium is not fully transparent when dry, it does not appear to alter the richness of Derivan colours in any way. Impasto Medium is also suitable for use as a light modelling compound.It can be applied by knife or brush in heavy blobs onto the original primed canvas and when dry, fully over-painted with Derivan colours.Do not use Impasto as a transparent glue or size where its slightly milky opacity could cause some discolouration. However, it makes a high quality acid-free glue or size where transparency is not a concern.