DL, C6/5, C5 and C4 branded envelopes: which format fits?

A branded envelope is both document packaging and the recipient’s first physical contact with a brand. It should protect the contents, suit the packing process and identify the sender clearly. Format selection should therefore begin with the document and folding method, followed by graphic design.

Popular formats

• DL (110 × 220 mm) - a common choice for an A4 sheet folded into thirds.
• C6/5 (114 × 229 mm) - slightly roomier than DL and practical for transactional mail.
• C5 (162 × 229 mm) - holds A4 folded in half and suits documents that should not be folded three times.
• C4 (229 × 324 mm) - for unfolded A4 documents, contracts, catalogues and larger sets.

Window or no window?

A window envelope removes separate addressing but requires a precise document layout. With automatically generated correspondence it can streamline production considerably. A non-window envelope offers more design freedom and suits addresses printed directly on the envelope or applied as labels.

What should the design include?

The logo and sender details should be clear without competing with the address area, postal markings or closure zone. The strongest design is simple, repeatable and suitable for both short runs and high-volume production.

How can expensive mistakes be avoided?

1. Test the real document in the selected envelope.
2. Check the address position after folding.
3. Allow for the thickness of the complete document set.
4. Approve a colour and technical proof before production.

The right format works with the document, equipment and dispatch method. The envelope then strengthens the company image rather than complicating everyday mailing.

Frequently asked questions

Which format suits A4 folded into thirds?

DL or the slightly larger C6/5 are the most common choices.

When should C4 be used?

When A4 documents must remain unfolded or the item contains a larger set of materials.

← Back to all articles