What is a Security Envelope
A security envelope is an envelope that has a pattern printed on the inside so that when it is held up to the light, the contents of the envelope cannot be seen. Unlike most envelopes that are somewhat transparent when held to light, the inside pattern provides a protective barrier. The envelope and inside pattern can be any color or style, but the most common are a #10 or #11 business envelope in white with a blue or black inside pattern.
What are Security Envelopes Used for
Security envelopes can be used for any documents or letters that you wish to keep confidential. They are commonly used in business when sending out important documents or contracts. However, they are typically used the most when sending money (check, money orders, travelers checks,etc.). The added security pattern helps decrease the chances of the money being stolen or tampered with.