Profitable and protected: Use the high-security Primary Color Booked Gift Certificate with Duplicates to let customers offer presents without risk of fraud. Comes with matching envelopes, a display sign and a door/window decal. Every certificate has chemically sensitive paper, a security screen and a clearly worded warning on the certificates. Visible security features include heat-sensitive ink and microprinting. A multi-dimensional foil seal is hot-stamped on back, offering seven security features. Add consecutive numbering to prevent duplication.