Top opening envelopes can be Banker envelopes, Wallet envelopes or Booklet Mailer's. Wallet and Booklet Mailer's are either Lick-Seal, Self-Seal or Peel & Seal envelopes. Banker envelopes have a V shaped closure flap and are only Lick-Seal envelopes.
Side opening envelopes are also called Pocket envelopes. These are available as either Lick-Seal or Peel & Seal envelopes.