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Envelopes are an important part of any business as they are what you send customers and suppliers your letters or mailings in. At AOS Online we stock a wide range of envelopes in different styles, colours and with or without a window. Choosing the right envelope can be daunting so we have created a full envelope size guide which can be viewed here.

Envelope types & sizes

Envelopes come in all different sizes, weight, styles and colours. The most common of sizes are C4, C5, C6 and DL. These correspond to the A4, A5 and A6 size paper.

All envelopes are measured with the Flap / Sealing Edge to the top, regardless of style. The second dimension of an envelope is always the flap / sealing edge.

The window is measured in the same way. Window depth first, width is second, Position up from the bottom is third and position in from the length fourth.

Envelope Seals

There are 3 different types of envelope seals which include:

  • Gummed: This is where an adhesive flap has to be moistened first before being stuck to back of envelope.
  • Press seal: This type of seal is most popular and has two adhesive flaps that when pressed together react and create a seal. In some cases press seal envelopes can be opened and closed repeatedly.
  • Peel and seal: This type provides the most secure seal and has an adhesive flap with a protective removable paper strip. Once removed and stuck to the back of the envelope it provides a strong secure seal.

In addition to the standard office envelopes, we also supply Airmail, CD/DVD, Executive, Internal Mail, Mailing Pouches, Padded and Bubble, Protective and Wage envelopes.

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