# item.guide
Side-by-Side Comparison C-Series Envelopes (ISO 269)

C6 Envelope vs. DL Envelope

Comparing 2 standards across 10 specifications. 10 key differences identified.

Comparing:
C6 Envelope
DL Envelope

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.

View full C6 Envelope spec sheet →

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.

View full DL Envelope spec sheet →

Specification Comparison Table

10 Parameters
Parameter / Spec
Width × Height (Metric)
114 × 162 mm 110 × 220 mm
Width × Height (Imperial)
4.49 × 6.38 in 4.33 × 8.66 in
Target Paper Pairing
A4 folded into quarters (105 × 148 mm) or flat unfolded A6 cards/postcards Standard A4 sheet folded in thirds horizontally (99 × 210 mm)
Paper Insertion Clearance
+9 mm width / +14 mm height clearance +11 mm height / +10 mm width clearance
Geometric Mean Origin
Geometric mean of A6 (105×148 mm) and B6 (125×176 mm)
Weight of Empty Envelope
~4.0 to 5.5 grams
Primary Applications
Personal handwritten letters, greeting cards, holiday cards, RSVP response cards
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)