Which type of paint is considered the most porous?

Flat paint is considered the most porous type of paint. This characteristic stems from its composition, which typically contains a higher degree of binder to pigment ratio compared to other finishes. As a result, flat paint has a matte surface that allows it to absorb more moisture and is more susceptible to staining. The porous nature of flat paint makes it ideal for ceilings and low-traffic areas, where the potential for abrasion and washability is less of a concern.

In contrast, gloss and satin finishes contain more binders and additives, which form a smoother, more reflective surface that is less porous and more resistant to moisture and stains. Eggshell paint also offers a slight sheen and is more durable than flat paint, contributing further to its resistance to absorption and staining.