Traditional natural varnishes, such as dammar, will yellow in time and the solvent used in their removal will dissolve or soften the acrylic paint layer. A water soluble varnish may be an answer. It is an issue that manufacturers might be able to address. Mold Growth Mold growth has been noted on acrylic paintings and has become an increasing concern among artists and collectors. Unfortunately, there is no ideal treatment that does not cause some degree of damage to the original paint.
Mold growth tends to become apparent when humidity and temperature rise.
Prevention is the best care. There are many trade acrylic paints that have been used by artists and the range in their quality is broad. The lesser quality paints tend to have cheaper colorants which fade easily under ultraviolet light. Thus, fading colors which change the tonal balance of the painting may be due to the intrinsic nature of the materials and can not be reversed by conservation. Summary Acrylic emulsion paintings have unique characteristics which require diligent preventative care.