Not recommended to paint over. Also offers UV protection. Refer to Golden Varnish Application Information for more details. Fast evaporation rate of alcohol makes this type of product idea for fixing the media. Not recommended to paint over.
Some brands can become brittle or yellow with age.
Be sure to read labels thoroughly. For best surface adhesion, apply Golden Acrylic Ground for Pastels over Golden Gesso. It may also be applied over other Golden acrylic mediums, gels, and paints for multi-media work. See GAC Specialty Acrylic Polymer Medium Information Sheet. For Pastel Can be used as a transparent gesso.