SEPARATED TREATMENT OF PAPER SUBSTRATE WITH MULTIVALENT METAL SALTS AND OBAs

摘要

A process for providing printable substrates by separately treating one or both surfaces of a paper substrate with an optical brightening agent (OBA) and a multivalent metal salt drying agent, where one or both surfaces of the paper substrate is treated with one of these two agents at the size press, and where the surface(s) is treated with the other of these two agents before or after the size press.