C6, C5 and C4 Envelope Sizes and What Fits Inside

Choose the envelope by the insert you want to send: C6 for A6 cards, C5 for A5 sheets or A4 folded once, C4 for unfolded A4.

✉️ Sizes and what fits

Size	Approx. dimensions	Orientation	Fits
C6	114 × 162 mm	Landscape	A6 cards, invitation pieces, A4 folded into quarters
C5	162 × 229 mm	Portrait	A5 flat or A4 folded once: proposals, certificates, invitation suites
C4	229 × 324 mm	Portrait	Unfolded A4: contracts, reports, certificates

⚠️ Warning: prepare artwork at the exact selected dimensions and matching orientation. Do not use a notecard or A-series page template as an envelope template.

💡 How to choose

Sending greeting cards or invitations: C6.
Sending an A4 letter folded once, or A5 flyers: C5.
Sending flat documents: C4.

Next, choose the stock: kraft or white.

❓ Frequently asked questions

Will an A5 notecard fit in a C6 envelope?

No. C6 suits A6 cards. Choose C5 for A5 sheets.

👉 Related guides and next steps