Stains have traditionally come in 3 categories: penetrating, film-forming, and acid stains. 

Film-forming stains have been around the longest, and as the name suggests, they simply lay or coat the surface.  

Penetrating stains penetrate the pores and bond to the concrete. Acid stains chemically react with the minerals in concrete to generate a natural-looking marble appearance by physically etching the surface.

Acid stains typically require more safety precautions and experience to apply than the film-forming and penetrating stains. 

Dyes are easy to use, have a large selection of colors, and are nonreactive. Dyes deliver color by penetrating concrete or other porous cementitious surfaces, such as overlays. Dyes are much smaller in particle size than chemical stains, thus allowing for easier penetration and color saturation. They typically come in a liquid dispersion or a powder, and are available in water-based or solvent-based options. 

Learn more in our QA on colored concrete. 

This stuff is complicated. Call us with any remaining questions you may have. We're here M-F, 8a-5p, CST, at 1-800-255-4255.