Using a custom return address rubber stamp for use on RSVP and Invitation envelopes. After stamping all of the RSVP envelopes with a white pigment ink stamp pad, I discovered that the ink was smearing when touched & also onto the other envelopes when stacked.. I left them overnight to dry but they are still smearing when touched, leaving a chalky residue on my fingers. Has anyone had this problem or have advice? Will a fixative spray work?