Side-by-Side Comparison
C-Series Envelopes (ISO 269)
C4 Envelope vs. C5 Envelope
Comparing 2 standards across 8 specifications. 8 key differences identified.
Comparing:
C4 Envelope
C5 Envelope
The C4 envelope is an ISO 269 standard postal packet measuring 229 × 324 mm (9.02 × 12.76 inches). Sized specifically to enclose a full unfolded sheet of A4 paper (210 × 297 mm) with comfortable margin, it is the worldwide standard for mailing legal contracts, university diplomas, annual corporate reports, and magazines.
The C5 envelope is an ISO 269 standard postal envelope measuring 162 × 229 mm (6.38 × 9.02 inches). Designed to enclose an A4 sheet folded once in half (V-fold) or an unfolded flat A5 document (148 × 210 mm), it is standard for greeting cards, invitations, company invoices, and small paperback book shipments.
Specification Comparison Table
8 Parameters| Parameter / Spec | ||
|---|---|---|
|
Width × Height (Metric)
|
229 × 324 mm | 162 × 229 mm |
|
Width × Height (Imperial)
|
9.02 × 12.76 in | 6.38 × 9.02 in |
|
Geometric Mean Origin
|
Geometric mean of A4 (210×297 mm) and B4 (250×353 mm) | Geometric mean of A5 (148×210 mm) and B5 (176×250 mm) |
|
Target Paper Pairing
|
Unfolded A4 paper (210 × 297 mm) or flat-folded A3 sheet | A4 folded in half (148 × 210 mm) or flat unfolded A5 stationery |
|
Paper Insertion Clearance
|
+19 mm width / +27 mm height allowance | +14 mm width / +19 mm height clearance |
|
Primary Applications
|
Legal contracts, commercial catalogs, official certificates, passport mailings | Greeting cards, event invitations, invoices, corporate brochures |
|
Common Variants
|
Pocket (short-edge flap opening) or Banker/Wallet (long-edge opening) / Board-backed 'Do Not Bend' | — |
|
Window Options
|
— | Standard left-hand or right-hand clear address window (45 × 90 mm) |