H 1565 (OTTO) p-Hydroxy azobenzene Cas 1689-82-3 - used to varnish, grease, paraffin wax, resin, soap kind of coloring. H 1565 (OTTO) p-Hydroxy azobenzene Cas 1689-82-3 - used in printing/solvent based writing inks. H 1565 (OTTO) p-Hydroxy azobenzene Cas 1689-82-3 - used for providing transparent metallic effects like gold imitation provided on metalized polyester films.