Heidi Swapp-Minc Christmas Envelopes, Inserts & Seal Stickers. The perfect finishing touch to your Christmas cards! Use with the Minc foil applicator and foil to give them a unique shine (sold separately). This package contains six 4-1/4x5-3/4 inch white envelopes, six inserts and six seal stickers. All inserts and seals are in black print. WARNING: This product contains chemicals known to the State of California to cause cancer, birth defects or other reproductive harm- do not mouth or chew. Imported.