Is a poly mailer a large envelope

A poly mailer is a type of envelope, but it's not necessarily a large envelope. The term "poly mailer" refers to a specific type of envelope made of polyethylene or polypropylene plastic, which is flexible and lightweight.

Poly mailers are often used for shipping small to medium-sized items, such as:

They are typically smaller than large envelopes, which are usually used for shipping larger or bulkier items. Large envelopes are often referred to as "flat rate envelopes" or "jumbo envelopes" and are designed to accommodate larger items, such as:

Here are some general size comparisons between poly mailers and large envelopes:

Keep in mind that these are general size ranges, and actual sizes may vary depending on the manufacturer and specific product.