Although the most common envelopes we are familiar with are those that are half a letter size or smaller, and usually carry simple papers and documents, there are others, also called pouches, whose function extends much further.
Traditional. Traditional envelopes are usually larger in width than in length, so you will be able to include your letter and legal size papers without any problems when folded vertically. These are usually used to send letters, invitations, greeting cards, invoices, postcards, money and the like.
The materials commonly used in this area are bond paper, cardboard and kraft paper, depending on the model and design you want to achieve, as well as the strength you prefer to obtain. You can find versions with light adhesive or without adhesive.
Bag. These usually carry heavier and more delicate material, such as documents that include several sheets, books, CDs and other papers that do not need to be folded. These envelopes are ideal, as their length allows the inclusion of several pages without having to fold or damage them to fit inside.
They usually have strong, light or no adhesive, depending on what you want to include, its nature and weight. Although kraft paper is usually the most commonly used, you can also find combined or all-plastic paper, as well as padded versions (with bubble wrap) to protect the contents.