C4 Envelope vs. DL Envelope
Comparing 2 standards across 10 specifications. 10 key differences identified.
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 DL envelope (Dimension Lengthwise / DIN Lang, standardized under ISO 269 and DIN 678) measures 110 × 220 mm (4.33 × 8.66 inches). Engineered specifically to hold an A4 sheet folded horizontally in thirds (Z-fold or C-fold), it is the dominant standard across Europe and most of the world for automated corporate billing, bank statements, and commercial direct-mail advertising.
Specification Comparison Table
10 Parameters| Parameter / Spec | ||
|---|---|---|
|
Width × Height (Metric)
|
229 × 324 mm | 110 × 220 mm |
|
Width × Height (Imperial)
|
9.02 × 12.76 in | 4.33 × 8.66 in |
|
Target Paper Pairing
|
Unfolded A4 paper (210 × 297 mm) or flat-folded A3 sheet | Standard A4 sheet folded in thirds horizontally (99 × 210 mm) |
|
Paper Insertion Clearance
|
+19 mm width / +27 mm height allowance | +11 mm height / +10 mm width clearance |
|
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' | — |
|
Primary Applications
|
Legal contracts, commercial catalogs, official certificates, passport mailings | — |
|
Address Window Position
|
— | Standard DIN window: 45 × 90 mm, located 20 mm from left, 15 mm from bottom |
|
Automated Insertion Standard
|
— | High-speed optical inserter machine standard (thousands of pieces/hour) |
|
Comparison to US #10
|
— | DL is 110 × 220 mm; US #10 is 4.125 × 9.5 in (104.8 × 241.3 mm) |