Impasto Medium is an oil painting medium of finely ground calcite, silica and bentonite in bodied linseed oil. Use it to extend paint without altering the consistency, making oil colors ‘short’ and buttery for impastos. Stiffer than Velázquez Medium, this putty-like medium makes colors slightly transparent while allowing you to build impasted, thick applications of paint. When added to oil paint, Impasto Medium does not alter its color temperature. It can be thinned with solvent or oil. Depending upon the proportion added to paint, Impasto Medium does not affect the drying time significantly.
Impasto Medium does not contain stearates, solvents, driers or natural or synthetic resins, so it is safe to add to oil paint without the worry of cracking or delaminating.
Impasto Medium is a calcite-rich oil-painting medium.
The soft white paste has little affect on oil colors, making them less opaque and slightly less saturated. Use it to build thick applications of color.
Comparison of Impasto Medium (top left) and Velázquez Medium (top right) shows the different handling characteristics added to paint.
Impasto Medium slightly increases the transparency of colors while maintaining the buttery consistency. It allows you to build impasto or thick paint with ease. When added to oil paint, brushstrokes hold their form without slumping or leveling. In the example above, when added to green earth artist oil (bottom center), the mixture of Impasto Medium (bottom left) extends the color and its consistency, while the mixture with Velázquez Medium (bottom right) gives the paint a long, ropy consistency.
Mix Impasto Medium directly into your paint right on the palette.
Impasto Medium is a great way to add calcite to your own paint. Add Impasto Medium and linseed oil directly to dry pigment powder until a stiff paste is obtained (almost the consistency of putty). Grind the paste with a muller on a flat surface before storing in collapsible tube. Some of its properties will be temporarily lost when grinding Impasto Medium with a muller, but should be restored when allowed to stand.