Personalizable Wedding Invite Envelope Stamps - See many more special Customisable Stamps For Weddings from the wedding postage designer at Artistic Postage. Round Thank You Stickers For Gifts And Envelopes. These elegant custom green and purple thank you stickers are perfect to use as envelope seals for thank you cards. Use them on the outside of a wrapped gift or gift bag. Great for thanking your guests for showing up at your wedding, anniversary, birthday party, graduation, bridal shower, baby shower, Holiday party and any other special occasion.