#1 Coin Envelopes (2 1/4 x 3 1/2) in Pool blue are perfect for holding small items and collectables. This multifunctional envelope is designed like a standard-sized envelope, but a miniature version. With a secure, moistenable flap, this is the ideal envelope if you're looking to store your coin collection, stamp collection, organize manufacturing parts or any small inventory items. Constructed from 80lb. cover, LUX Pool is a bright, saturated blue that is sure to make a make a splash among recipients. Please note that this envelope size is not mailable via USPS.