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

C5 Envelope vs. DL Envelope

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

Comparing:
C5 Envelope
DL Envelope

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.

View full C5 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)
162 × 229 mm 110 × 220 mm
Width × Height (Imperial)
6.38 × 9.02 in 4.33 × 8.66 in
Target Paper Pairing
A4 folded in half (148 × 210 mm) or flat unfolded A5 stationery Standard A4 sheet folded in thirds horizontally (99 × 210 mm)
Paper Insertion Clearance
+14 mm width / +19 mm height clearance +11 mm height / +10 mm width clearance
Geometric Mean Origin
Geometric mean of A5 (148×210 mm) and B5 (176×250 mm)
Window Options
Standard left-hand or right-hand clear address window (45 × 90 mm)
Primary Applications
Greeting cards, event invitations, invoices, corporate brochures
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)