Porosity of acrylics

According to Eliyahu Mirlis, a New Jersey-painter, the porosity of acrylics is recognized as positive in some applications to allow water vapor to pass through the paint film, reducing the risk of delamination. The porosity of acrylic also provides exceptional mechanical adhesion of the acrylic paint layers to each other. Of course, a porous paint film on artwork has many implications for painters and conservators.

A porous coating can trap air pollution, dirt, and foreign matter, promoting biological growth. This porous film can trap preservative cleaning agents, leaving highly concentrated solvent pockets that can interact with acrylic paint film over the long term, which can cause film weakening.