The term 'SANDPAPER SPEC' refers to the characteristics of sandpaper, which is a type of abrasive material used for smoothing and polishing surfaces. The two crossword solutions, GRIT (4 letters) and COARSE (6 letters), refer to the size of the abrasive particles in the sandpaper. GRIT is a measure of the size of the particles, with higher numbers indicating smaller particles, while COARSE indicates that the particles are larger.