Custom C4 Envelopes for Flat A4 Documents

Flap Styles and Closures

C4 envelopes come in two main shapes. Pocket envelopes open on the short edge, which suits documents fed in by hand or by a mail inserter that pushes papers lengthways. Wallet envelopes open on the long edge, which makes it easier to slip in a folder or a stapled bundle without bending it. Which one you need often comes down to the inserting machine in your post room, or the lack of one.

Peel-and-seal strips are the most popular closure because nobody has to lick or wet anything, and the seal stays strong once pressed. Self-seal envelopes have two gummed strips that bond on contact. Traditional gummed flaps are the lowest cost and still suit large mailings that run through a franking line with a moistener. p1 For plain brown post-room stock without print, see our manila envelopes in C4 and C5.

Windows, Return Addresses and Postal Layout

A window lets the recipient's address on the top sheet show through, so you print the address once and skip a label. Windows on C4 envelopes are positioned to match standard letter templates, and we can move them if your letterhead puts the address somewhere unusual. Send us a sample page and we will line the window up with your layout before the proof.

A printed return address on the back flap means undeliverable post comes back to you instead of disappearing. Keep the front clear in the area where postal machines read the address and apply stamps or franking. We leave that zone untouched by default and only print logos and brand panels where they will not slow the post down. p1 Address windows are also standard on our slim DL envelopes for letters, where the template is tighter.

Printing Options for Large Envelopes

A C4 front is a generous canvas, but most organisations keep it simple: a logo in the top-left corner, a strapline or website and the return address on the flap. Full-bleed colour across the whole envelope is possible and suits marketing mailings, where the envelope itself has to earn the opening. Spot colour printing in one or two inks is the economical choice for routine correspondence and matches brand colours closely.

Printing inside the envelope is a subtle way to add privacy. A tinted security pattern stops the contents being read through the paper, which matters for payslips, medical letters and financial statements. We can combine an inside pattern with outside branding on the same envelope. p1 The printed envelopes overview page shows one-colour and full-colour fronts side by side.

Matching C4 Envelopes to the Rest of Your Stationery

Large envelopes rarely travel alone in a stationery order. Most offices also use DL envelopes for folded letters and C5 for A4 sheets folded once, and it pays to plan all three together. Using the same paper shade, logo position and ink colour across the set means a client who receives three letters from you over a month sees one consistent identity rather than three slightly different ones.

If you already have printed letterheads or compliment slips, send a photo or a PDF and we will match the logo size and colour to them as closely as the paper allows. Uncoated envelope paper absorbs ink differently from a smooth letterhead, so a brand colour can look a shade softer on the envelope. Our proof notes flag where that is likely so there are no surprises.

For organisations that send both routine and ceremonial post, a two-tier approach works well: a practical white or manila C4 for everyday documents, and a heavier cream or coloured C4 reserved for diplomas, awards and formal invitations. The second set is ordered in smaller quantities and lasts longer.

Send a Filled Envelope's Weight With the Artwork

C4 envelopes fail in one of two ways: a thick welcome pack splits a light envelope at the seam, or a single-page letter travels in a heavy wallet that cost more than it needed to. So before you order, put a typical filled envelope on the post-room scales and tell us the weight and the number of sheets. That decides the paper weight, and often splits one order into a light pocket for letters and a heavier wallet for packs at about the same total cost.

Tell us also if a mail inserter is used, because that fixes pocket or wallet, and send a sample letter so the window lines up with your address block. The custom quote arrives by email within one working day, from £0.25 an envelope, with the minimum set per job so a small office is not buying a year's stock.

The free proof shows the print and window position on the flat envelope. Production takes 4 to 7 working days once approved, and the bundled cartons reach UK mainland addresses by free tracked delivery. Offices that send folded letters as well usually order C5 envelopes in the same print in the same job.