Custom Self Seal Mailer Boxes Made to Your Size

What is a self seal mailer box?

It is a one-piece corrugated mailer with a strip of adhesive already fixed to the lid flap. A thin paper liner covers the glue until you are ready to close the box.

The body folds from a single flat blank, much like our standard custom printed mailer boxes. The difference is the closure. Instead of a tuck held by friction or a run of tape, the lid is glued shut by the person packing it.

Do I need a tear strip as well?

A tear strip is a perforated pull tab cut into the front panel. The customer pulls it and the lid lifts away without scissors or a knife.

It pairs well with an adhesive seal because the glue is strong and the box is not meant to be prised open. If you skip the tear strip, buyers will cut through the board, which can damage what is inside. Ask on your quote if you also want a second glue strip for returns, and we will confirm whether your size allows it.

Self seal lid or plain tuck lid: which should I choose?

A plain tuck lid holds by friction alone. It is fine for gift boxes handed over in person, but in the post it usually needs tape across the front to stop it popping open.

The adhesive version removes that step and gives a cleaner finish, because there is no strip of tape across your print. It costs a little more per box than a plain tuck, since the glue and liner are added at the factory. If you pack fewer than a handful of orders a day, tape may be all you need. Once volumes grow, the time saved at the bench tends to matter more than the small extra cost.

Some sellers keep both: plain tuck boxes for local hand delivery, and the self seal style for anything going through the post.

What size self seal mailer do I need?

Measure the product, then add a small allowance on each side for paper fill or a card insert. We make the box to the inside length, width and height you give us, in mm, cm or inches.

Keep the height snug. A tall gap above the product lets it slide, and the adhesive lid will not pull the contents tight the way tape can. Our guide on measuring a box inside correctly walks through the method step by step.

Is a glued lid secure enough for the post?

For the goods these boxes usually carry, yes. The strip bonds along the whole front flap, so the lid cannot be lifted at a corner the way a loose tuck can.

Security also depends on fit. A product that fills the box keeps pressure off the lid, while an empty space invites the panels to flex in transit. For heavier items, choose B flute at about 3 mm and use paper fill so nothing shifts. If an item is breakable, wrap it on its own before it goes in, and keep the parcel weight sensible for a folding mailer. Very heavy orders are better suited to a corrugated shipping carton taped along the seams.

Which board suits a self seal mailer?

Most self seal mailers are single wall corrugated. The flute you choose sets the thickness and how the box feels in the hand.

Can the box be printed inside and out?

Yes. We print plain, one colour, two colour or full colour CMYK, on the outside, the inside or both. A message under the lid is a popular choice because it is the first thing seen once the strip is torn.

For a finish, pick from uncoated kraft, matte or gloss laminate, spot UV, foil stamping or embossing. Keep artwork clear of the glue strip and the tear line, as those areas are cut or covered. You can sketch the layout in Design Your Box on this site before sending files.