Abstract: This invention describes a method of treating papermakers' forming and press belts made from polyethylene terephthalate mono or multifilament yarns so that the belts substantially resist the deposition of pitch on the belt yarns while in use in a papermaking machine environment. Pitch-contaminated water and pulp mixtures in contact with the belts are subjected to suction and pressure pulses which remove water from the mixture. The belts are coated with a coating compound which is co-crystalline with the polyethylene terephthalate at the surface of the filament. The coating compound contains a profusion of oxalkylene groups to establish a hydrophilic barrier of active oxyalkyene groups by solvation with water to repel the pitch from the belt and to prevent clogging the belt.