Seeded Paper Envelopes - an important message to send? By using seed paper letterhead or envelopes, you're also sending a bouquet of flowers with each one - creating a greeting that's guaranteed to be remembered. 50gsm coloured or 80gsm white, with full colour print on front (up to 50% coverage) and growing instructions on the back. This envelope has a resin adhesive with tape liner for closing. Available in blue, yellow, orange, red and green.