Abstract: An in-lap mouse pad support has an essentially flat panel, with an upper surface for a computer mouse and an undersurface having a plurality of thin, orthogonally disposed walls, to form an array of rectilinear cells of uniform size, and at least one sidewall with two or more rounded connecting members, sized to fit tightly into a rectilinear cell, extending upwardly from the sidewall upper edge, so that the sidewall may be attached to the flat panel thereby.