Booklet envelopes have two side seams and an open side, meaning the longest side has a flap. Booklet Envelopes are specially designed for mailing and shipping larger documents and materials, such as catalogs, booklets, brochures, and other similar items that do not fit in standard-size envelopes. These envelopes are typically larger and have a side opening or a flap on the longer side of the envelope, making it easy to insert and remove the contents.
