There is a special ink, called "scratch off ink." It is "an opaque printing ink formulated to be applied on a substrate to hide the information already printed on the substrate and to be scratched off to reveal the printed information."
Originally posted by: FoBoT
http://www.answerbag.com/q_view/24557
There is a special ink, called "scratch off ink." It is "an opaque printing ink formulated to be applied on a substrate to hide the information already printed on the substrate and to be scratched off to reveal the printed information."
Originally posted by: FoBoT
http://www.answerbag.com/q_view/24557
There is a special ink, called "scratch off ink." It is "an opaque printing ink formulated to be applied on a substrate to hide the information already printed on the substrate and to be scratched off to reveal the printed information."