A coated abrasive of improved resistance to «ioading» comprising a flexible backing, a plurality of abrasive grit particles dispersed over the area of at least one surface of said backing, and at least one layer of adhesive bond ma- teriai adhering said abrasive grit particles to each other and to said backing, characterized by the fact that the outermost layer of said adhesive bond material comprises:
(a) animal giue, or a cured amino resin, or a mixture thereof in an amount of at least 40% by weight of the total adhesive bond material, exclusive of any filler; and (b) at least 0.74 grams per square meter of an additive which is (1) a mono-, di-, and tri-organyl ester of orthophosphoric acid, (2) a salt of a mono-, di-, and tri-organyl ester of orthophosphoric acid with an amine, (3) a tetraorganyiammonium sait, or (4) a soluble mixture thereof. Best results are obtained with a sizer adhesive of amino resin containing phosphate esters or their amine salts as additive.