Collection: C4 Envelopes (229 x 324mm)

C4 envelopes measure 229 x 324mm and are designed to hold A4 documents unfolded — brochures, reports, contracts, architectural drawings and large-format materials that should not be folded. With over 110 products across the range, there is a C4 envelope for every application — from standard business correspondence to premium invitation and colour-matched seasonal mailings.

Paper weights run from 22–350gsm, covering everyday use through to premium presentation. Closure options include gummed (lick-and-seal) and peel & seal. Available in a range of colour options alongside white and manilla.

What Fits in a C4 Envelope?

A C4 envelope (229 x 324mm) holds A4 unfolded documents, legal agreements, planning applications, A4 brochures, certificates, magazines. This makes it the standard choice for professional document mailings, brochures, contracts, architectural drawings, institutional correspondence.

Benefits of C4 Envelopes (229 x 324mm)

• Standard C4 format (229 x 324mm) — holds A4 documents unfolded — brochures, reports, contracts, architectural drawings and large-format materials that should not be folded.
• over 110 products — spanning white, manilla, coloured and specialist options.
• Paper weights 22–350gsm — from everyday to premium presentation weights.
• Closure options — gummed and peel & seal to suit both personal and volume workflows.
• Royal Mail compatible — qualifies as large letter or small parcel depending on contents weight and thickness within standard weight limits.
• a range of colour options — 44 shades available.

Frequently Asked Questions

What fits in a C4 envelope?
A C4 envelope (229 x 324mm) is designed to hold A4 unfolded documents, legal agreements, planning applications, A4 brochures, certificates, magazines. It is the standard size for professional document mailings, brochures, contracts, architectural drawings, institutional correspondence.

What paper weight should I choose for C4 envelopes?
90gsm for standard use; 120gsm for professional presentation; board-back variants available for bend-sensitive contents

Are C4 envelopes compatible with Royal Mail?
Yes. C4 envelopes (229 x 324mm) qualify as large letter or small parcel depending on contents weight and thickness in standard use. Always confirm the packed weight before assigning a postage rate, as the envelope itself contributes to the total weight. If you are mailing at volume, a small test batch before full despatch is recommended.

What closures are available for C4 envelopes?
The range includes gummed (moisture-activated, traditional) and peel & seal (self-adhesive strip) options. Gummed is the preferred choice for greeting cards and personal correspondence. Peel & seal is significantly more practical for business mailing at volume — faster, cleaner and more consistent.

Do C4 envelopes come in colours?
Yes — a range of colour options are available across the C4 range, covering white, manilla, bold primaries, pastels and metallics. Coloured envelopes in the C4 size are particularly popular for greeting cards and invitation campaigns.

Do C4 envelopes come with a window?
Yes — window variants of C4 envelopes are available, with a clear polypropylene panel that allows the address to show through the envelope. Window envelopes are widely used for business mailings, invoices and statements where the address is printed on the insert rather than the envelope.

Are gusset (expansion) C4 envelopes available?
Gusset (expansion) variants are available for thicker document packs — a 25mm gusset accommodates up to approximately 150 sheets of 80gsm paper.