Physical properties of sodium silicate-based substances make them very attractive for commercial/industrial use. Liquids and solids based on sodium silicate and produced by PQ Corporation have a density from 1.6g/cubic cm. to about 1.4 g/cubic cm.
A very big difference between acrylic and oil paint is the drying time. Acrylics dry in a matter of minutes to hours and oils dry in a matter of hours to weeks! This is a huge factor when choosing whether or not to choose oils versus acrylics.
Acrylic on top of wet watercolor. By painting with acrylic on top of still-wet watercolor, you can attain some very pretty, sheer-looking results. For instance, on the above image, white acrylic paint is applied over a still-wet wash of blue watercolor paint.