Vallejo Matt Medium (17 ml.) Is a colorless medium that is mixed with acrylic paints; it provides a matte finish for the acrylic paint. This medium can be used for almost any brand of acrylic paint. For example for Vallejo Model Color, Vallejo Game Color and Formula P3 paint.
For example, Matt Medium can be very well used to simulate fabrics on thumbnails. This makes the material appear softer. It is not a varnish, but is used during the application of the paint, so that the rest of the miniature does not have to get "matte" varnish.