What paint finish or sheen is best for hiding plaster imperfections on large walls?

A flat matte or eggshell finish is highly recommended for hiding minor imperfections on wall surfaces. High-sheen paints, like semi-gloss, reflect light in uniform, mirror-like angles that emphasize surface wave and trowel marks. Matte and eggshell finishes diffuse light unevenly in multiple directions, successfully concealing minor physical variations in the underlying plaster layer.