International paper sizes and envelope sizes guide

The system is based on three series of sizes all of the same proportion, designated A, B and C.

The A series for stationery and general leaflet printing.

The B series is intended primarily for larger printed items such as posters , wall charts etc.

The C series, in conjunction with some of the B sizes, is used for envelopes.

The above chart illustrates the constant ratio between the long and the short sides of the sub-divisions of an A1 sheet. The constant ratio means that any drawings, artwork, diagrams or typesetting prepared for one size in the series, will be in proportion to any other international paper size (A, B or C) up or down.

The popular stationery sizes are A3, A4 and A5.

Envelope 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.

DL Envelopes - DL envelopes are the standard size for business letters as they take an A4 sheet folded twice into 3 parts.

C6 Envelopes - C6 Envelopes are used largely for invitations or handwritten letters with standard notepaper. It will also take an A4 sheet folded twice into quarters or an A5 sheet folded in half.

C5 Envelopes - C5 Envelopes are fast becoming the most popular envelope for sending out correspondents as they are cheaper to send with Royal Mail than the C4. C5 envelopes will take an A4 sheet folded in half or an A5 sheet unfolded.

C4 Envelopes - C4 Envelopes are ideal for Magazines, catalogues or A4 brochures as no folding is required. For larger size brochures, a Gusset version is available.

C3 Envelopes - C3 Envelopes are one of the largest envelopes available and are designed to take prints, plans or photocopies.

Envelope Types

Envelopes come in many different types and styles.

Plain - Designed for writing on or for use with address labels

Window - 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.

Gusset - Expandable envelopes for sending multiple sheets or small catalogues.

Board Back - Printed with "Please Do Not Bend" for programmes, certificates, photographs, diplomas etc.

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.

Besides our own brand, Q Connect, we also hold ranges from Plus Fabric, New Guardian, Basildon Bond, Owl, Conqueror, Character, John Dickinson, Versapak, AirKraft, Jiffy, Mailmiser, 3 Candles, Elco, Lion, Postmaster and Tyvek.

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