Method and composition for obtaining waterfast images from ink jet inks

摘要

A method for use with dye-based ionic ink jet inks is disclosed whereby the ink jet ink becomes substantially waterfast upon application to a print substrate. The method includes treating a print substrate with a precipitant composition and jetting an ionic ink jet ink onto the print substrate, wherein the precipitant composition includes water and an ionic precipitant of opposite ionic charge from the ionic ink jet ink. The print substrate may be treated during formation of the print substrate or after formation of the print substrate and before jetting the ionic ink jet ink onto the print substrate. By this method, the ionic precipitant composition reacts with the oppositely charged ionic ink jet ink to form a precipitant on the print substrate that is substantially waterfast.