Staining paint is a term often used in art and home improvement to describe two distinct concepts: a specific fine art technique and a category of protective wood coatings. 

Wood Finishing (Paint vs. Stain)

In home improvement, staining paint refers to using a pigmented wood stain that behaves differently from traditional paint. 

Penetration: While paint forms a thick, opaque film on top of a surface, a stain is thinner and designed to penetrate porous materials like wood.

Visibility: Stains are formulated with lower binder-to-solvent ratios, allowing the natural grain and texture of the wood to remain visible.

Solid Stains: Some products, known as “solid stains,” are a middle ground; they provide a more uniform, paint-like color but still penetrate the surface rather than forming a surface-level barrier. 

Pigment Property (Watercolor)

In watercolor painting, “staining” refers to the ability of certain pigments to anchor themselves permanently into the paper fibers. 

Non-staining: Colors that can be “lifted” or wiped off with a wet brush after drying.

Staining: Colors (like Phthalo Blue) that dye the paper immediately and cannot be easily removed or corrected.