Side-by-Side Comparison
C-Series Envelopes (ISO 269)
C4 Envelope vs. C7/C6 Envelope
Comparing 2 standards across 9 specifications. 9 key differences identified.
Comparing:
C4 Envelope
C7/C6 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 C7/C6 envelope is an ISO 269 hybrid envelope format measuring 81 × 162 mm (3.19 × 6.38 inches). Having the height of a C7 envelope and the width of a C6 envelope, it is engineered specifically to hold an A5 sheet folded in thirds, widely used for confidential payroll slips, dividend checks, and gift vouchers.
Specification Comparison Table
9 Parameters| Parameter / Spec | ||
|---|---|---|
|
Width × Height (Metric)
|
229 × 324 mm | 81 × 162 mm |
|
Width × Height (Imperial)
|
9.02 × 12.76 in | 3.19 × 6.38 in |
|
Target Paper Pairing
|
Unfolded A4 paper (210 × 297 mm) or flat-folded A3 sheet | A5 paper folded horizontally in thirds (70 × 148 mm) |
|
Paper Insertion Clearance
|
+19 mm width / +27 mm height allowance | +11 mm height / +14 mm width clearance |
|
Primary Applications
|
Legal contracts, commercial catalogs, official certificates, passport mailings | Confidential employee salary pay-slips, dividend warrant checks, gift certificates |
|
Geometric Mean Origin
|
Geometric mean of A4 (210×297 mm) and B4 (250×353 mm) | — |
|
Common Variants
|
Pocket (short-edge flap opening) or Banker/Wallet (long-edge opening) / Board-backed 'Do Not Bend' | — |
|
Hybrid Geometry Origin
|
— | Height of C7 (81 mm) combined with Width of C6 (162 mm) |
|
Common Security Features
|
— | Dark opaque blue/black cross-hatch security pattern interior print |