Side-by-Side Comparison
C-Series Envelopes (ISO 269)
C3 Envelope vs. C6 Envelope
Comparing 2 standards across 9 specifications. 9 key differences identified.
Comparing:
C3 Envelope
C6 Envelope
The C3 envelope is an ISO 269 standardized large postal packet format measuring 324 × 458 mm (12.76 × 18.03 inches). Designed specifically to hold flat, unfolded A3 documents (297 × 420 mm) or thick bound A4 portfolios, it is the standard packaging for architectural presentations, financial ledgers, and artwork shipments.
The C6 envelope is an ISO 269 standard compact postal envelope measuring 114 × 162 mm (4.49 × 6.38 inches). Designed to enclose an A4 sheet folded in half twice (cross-folded in quarters) or an unfolded A6 picture postcard (105 × 148 mm), it is the global standard for personal correspondence, holiday cards, and gift certificates.
Specification Comparison Table
9 Parameters| Parameter / Spec | ||
|---|---|---|
|
Width × Height (Metric)
|
324 × 458 mm | 114 × 162 mm |
|
Width × Height (Imperial)
|
12.76 × 18.03 in | 4.49 × 6.38 in |
|
Geometric Mean Origin
|
Geometric mean of A3 (297×420 mm) and B3 (353×500 mm) | Geometric mean of A6 (105×148 mm) and B6 (125×176 mm) |
|
Target Paper Pairing
|
Unfolded A3 (297 × 420 mm) or bound A4 spiral/comb portfolios | A4 folded into quarters (105 × 148 mm) or flat unfolded A6 cards/postcards |
|
Primary Applications
|
Architectural drawings, financial balance sheets, graphic design proofs, diploma certificates | Personal handwritten letters, greeting cards, holiday cards, RSVP response cards |
|
Standard Paper Clearance
|
+27 mm width / +38 mm length allowance for easy insertion | — |
|
Common Closure Types
|
Peel-and-seal strip, string-and-button, cardboard gusset pocket | — |
|
Paper Insertion Clearance
|
— | +9 mm width / +14 mm height clearance |
|
Weight of Empty Envelope
|
— | ~4.0 to 5.5 grams |