Standard Size Envelope The #10 envelope is a versatile size, perfect for mailing checks, invoices, personal letters, statements, and so much more! Sometimes called a "letter" or "legal" envelope, this is most commonly used to store letterhead paper that is folded into thirds. Moistenable Glue Seal These envelopes are designed with a traditional moistenable adhesive sealing method. Simply moisten the strip of adhesive, apply pressure, and you’ll have the perfect seal. It couldn't be easier! Easily Personalize by Using a Printer or Writing by Hand Compatible with most digital and offset printers, these envelopes are easy to customize. Want more of a DIY look? Gel Pens, Calligraphy and other hand crafts look amazing! Envelopes.com is a leading e-commerce business offering a large in-stock selection of sizes, styles and colors to serve millions of consumers and businesses alike. Through years of ever-changing communication and technology, Envelopes.com has remained at the top of its industry through constant innovation, product expansion and always putting customer needs first.