Box styles
Box styles4 min readUpdated
Mailer boxes
A mailer box is cut from one sheet of corrugated board and folds into a tray with a hinged lid. Nothing is glued: the walls and the lid lock into each other. So the box stays flat until you pack it, folds up by hand and opens again for a return.
How a mailer locks
Our mailer box follows FEFCO 0427FEFCO code A four-digit code for a corrugated box style from the FEFCO catalogue, such as 0201 for the regular slotted carton. It names the shape, not the size., the classic e-commerce mailer. Fold it in this order and you can see why it needs no tape:
- The front and back walls fold up, and the small end flaps at their corners fold in.
- Each side wall is double. It folds up, over and back down inside, holding the end flaps between its two layers, and a small tongue on its edge drops into a slot in the floor.
- The lid comes over from the back wall. Its side flaps slide into the side walls, and its front flap goes in behind the front wall, with two ears that slip into the double side walls.
The fold at the top of each side wall is two creasesDouble crease Two creases side by side, twice the board thickness apart, where a wall folds right back on itself. Under 0.6 mm one crease is enough., two board thicknesses apart, so the board has room to turn back on itself; board under 0.6 mm gets a single crease. The board thicknessBoard thickness How thick the board is, in mm, also called caliper. Type it into a box's dieline and the details around the folds follow it. changes only the details around the folds: the floor stays the length × width you type. Structural features says more about double walls.
The styles in the Style list
| Style | FEFCO | What changes |
|---|---|---|
| Ears | 0427 | The default: the lid's front flap has ears that tuck into the double side walls. |
| Tuck | 0429 | The same lid with a plain front flap, no ears. |
| Plain lid | 0421 | No side flaps on the lid, and a short front flap, half the wall height. |
| Double front | 0426 | The front wall is the double one and locks into the floor. The side walls are single, and their front corner flaps fold into the front wall. |
| Double front, ears | 0475 | The double front wall with the eared lid. |
Try each style
Open a mailer box and switch Style. The lid or the double wall changes with each FEFCO code, and your sizes stay as they are.
- Cut
- Crease
Two more mailers
- Tab lock mailer box. On the tab lock mailer box the double end walls hang on the back wall and roll over the front wall's flaps. An inner lid folds in first, then a tab on the front wall snaps up through a slot in the lid, so the box doesn't pop open if a parcel is dropped. It takes corrugated boardCorrugated board A wavy sheet, the flute, glued between flat liners. Light, stiff and hard to crush: the board of shipping and mailer boxes. from 1.5 to 3 mm; see the tab lock mailer sizes.
- Shallow mailer box. The shallow mailer box is a low mailer drawn from a real production die. Its two end walls are double and lock into the floor with two tabs each, holding the corner flaps of the front and back walls between their layers. It suits flat things: prints, documents, thin gifts.
Mailer or shipping box?
A shipping box is a glued tube with four flaps at each end that you tape shut. Which of the two takes less board depends on the shape: for a tall box the shipping box's blank is smaller, for a flat one the mailer's can be. Compare the overall sizes on the two drawings. A mailer needs no tape and opens like a lid on a box, which is why e-commerce shops and subscription boxes use it. Shipping boxes and FEFCO codes covers the whole carton family.
Our mailer starts on E fluteE flute A thin corrugated flute, 1.5 mm in our Board list. Flat enough to print well, it suits mailer boxes and retail packs., 1.5 mm, thin and smooth to print; our shipping box starts on B flute, 2.8 mm. Flute profiles compares them.
Printing a mailer
A mailer is printed like any corrugated box: straight onto the board's outer paper, or on a separate sheet that is glued onto the board, for photos and fine detail. Corrugated liners and Printing methods explain both. For a small run, a plain mailer with a printed label or sticker works too.