Envelopes are a very important detail in everyday business communication. Although many predicted their gradual disappearance with the advent of a new era on the Internet, research shows the opposite. They can be of different sizes, the envelopes can be windowless, with a left window and a right window. Today, much more attention is paid to their visual effect and originality, because in this way you present yourself to your customers as a company that cares about its corporate identity.