Sizing mailer boxes for e-commerce

Start from the packed contents

Lay out everything that goes in: products, tissue, inserts and printed cards. Measure the group as it will be packed. Add 3 to 5 mm on each dimension for corrugated, more if you use crinkle paper or air pillows.

Check the postal rate bands

Postal services price parcels by size bands and weight. The outside of a corrugated mailer is about two board thicknesses larger than the inside on each axis: roughly 3 mm with E-flute and 6 mm with B-flute. Check the outside size against your carrier’s band before you finalise the inside size.

E-flute or B-flute

E-flute (about 1.5 mm) prints crisply and folds neatly, and suits most subscription and fashion mailers. B-flute (about 3 mm) protects better for heavy or fragile items and stacks more strongly in transit. Many brands use E-flute for products under about 2 kg.

Choosing the mailer style

The roll-end family covers most needs:

• Roll-end tuck front: the classic subscription box, lid tucks over the front.
• Ear-lock mailer: ears lock the lid for repeated opening.
• Roll-end tuck top: a cleaner top edge for retail-style packs.
• Peel-and-seal: adhesive closure for fast packing and returns.

Print inside and out

Printing inside the lid adds a moment to the unboxing at modest cost. Keep important artwork away from the rolled walls, which fold over, and remember that the lid tuck covers part of the front.

Common questions