A1 / 4-BAR Envelopes – What is an A1 Envelope?

A1 Envelopes which are technically listed among Baronial Envelopes and properly named a 4-BAR Envelope. A1 is a common name but not technical. 4BAR is the industry name and we use A1 along side as to correspond to other A-SIZE envelopes offered on our site.

The dimensions of A1/4BAR envelopes is a North American standard amongst envelope converters. If you want a square flap, you would generally order as “4-Bar Square Flap” and if you need a pointed flap, this is specifically a 4-Bar Envelope.

We at Paper-Papers use the term interchangeably since the dimensions are the same and the photo next to the products, along with the description, will describe the flap or envelope style.

This envelope is the smallest member of our Announcement Envelopes, many times referred to as Response Envelopes, 4Bar Envelopes or Wallet Envelopes. Noting this to be the smallest announcement envelope allowed by the Postal service, many designers choose this size as a popular option for “replies” (RSVP) of formal invites.

A1 & 4 BAR (same size) – Envelope Dimensions:

• Inches: 3.625 x 5.125 (3-5/8 x 5-1/8)
• CM: 9.2075 x 13.0175
• MM: 92.075 x 130.175

Enclosure choice is not as strict as the actual dimensions. Truly finalized by the designer, the enclosure simply needs to be dimensions smaller than the envelope itself. A general rule of thumb is allowing .25 inches in height and width.

As many creative hearts already know, the bulkier the enclosure, the more room necessary to properly insert, close and seal. Listed below is suggested enclosure dimensions to assist toward a successful creation!

Suggested enclosure dimension:

• Inches: 3.375 x 4.875
• CM: 8.5725 x 12.3825
• MM: 85.725 x 123.825

View our hundreds of 4-Bar / A1 Envelope options or continue your research by reviewing a list of popular Envelopes and understanding their sizes.