There are several kinds of envelopes used in the business world today. Standard Mailing Envelopes, Catalog Open End Style, Booklet Open Side Style, Window Envelopes, Remittance Large Flap Envelopes, Self Seal Envelopes, Jumbo Size Extra Large Envelopes, printed envelopes, Small Coin Style Business Envelopes and Envelopes with a Clasp Closure are some of the more commonly used envelopes.