Double-Sided Printed Mailer Boxes

How Double-Sided Printed Mailer Boxes Are Made

Most mailers are E-flute or B-flute corrugated board. To print both sides, we print the outer liner and the inner liner separately before they are laminated to the fluting, or print litho sheets that are then mounted. Either way, the two printed faces are registered to the same dieline so the inside design lines up with the folds and the lid.

Because both faces carry ink, the board choice affects how the colours look. White liners on both sides give the brightest results; kraft outside with white inside is a popular mix that keeps the rustic look on the doorstep and saves the bright colour for the reveal. Matt or gloss lamination on the inside surface makes colours richer and protects them from fingerprints.

Ink coverage inside also affects the feel of the box. A full flood of dark colour can make the interior look dramatic, but it shows scuffs from products sliding in. A lighter background with a pattern hides packing marks better and still gives a strong reveal. Liner colours and flutes are compared in our guide to board and card types.

Choosing the Right Mailer Size

Measure the product plus any tissue, inserts or printed cards you add. Then allow a few millimetres all round for easy packing. A mailer that is too big lets products slide around and look lost when opened, which spoils the reveal you have just paid to print; too tight and staff struggle to pack it quickly.

If you send several products in different combinations, try to standardise on two or three box sizes. A fitted insert can hold smaller items in a larger box, keeping the presentation neat without needing a new box size for every order.

Remember courier size bands. A box a few millimetres smaller can fall into a cheaper parcel size, which adds up across hundreds of orders.

When you have the size, pack a sample order in a plain box of the same dimensions and open it as a customer would. Check where the product sits relative to the lid message, because the best interior print is the one that is not hidden under the product itself.

Making the Inside Work Hard

A printed interior is most effective when it is useful as well as pretty. Good inside messages are short: a greeting with the customer's first name space left blank for handwriting, a line about how the product was made, a reminder to tag the brand, or a prompt to reorder. Long blocks of text inside a box rarely get read.

Many brands also use the inside flap to hold a small printed card or a sample. A slot cut into the inner wall can grip a card or a sachet, so it is the first thing seen when the box opens.

If you change messages for promotions or collaborations, keep the main pattern on the box and use a printed card for the changing message. That keeps print runs long and costs down.

A QR code inside the lid that leads to a care guide, a styling page or a reorder link turns the box into a route back to your shop rather than just a container. Sets with bottles that need holding in place are drawn as mailer boxes with a fitted insert before the print is placed.

Brands That Use Them

Subscription boxes, beauty and skincare brands, fashion labels, gift companies and premium food and drink brands are the most common users. Anyone whose customers share unboxing photos benefits. Corporate teams also use them for client gifts and onboarding packs, where an inside message from the company sets the tone.

Smaller online shops often start with a printed outside and plain inside, then add interior print once they see how much engagement the unboxing gets.

For teams packing a few dozen orders a day, these boxes also simplify packing. Without separate tissue, stickers and cards for every parcel, the box itself does the presenting, and packing benches stay quicker and tidier. Premium gift brands that want a rigid feel with the same two-sided print move to luxury mailer boxes in heavier board.

Write the Inside Message Before the Outside Artwork

Double-sided mailers are ordered back to front. Write the inside first, the line a customer reads as the lid lifts, the pattern on the walls, the slot for a card, because that is the part the customer remembers; then let the outside carry only the logo and a return address. Decide the liner pairing from that: white inside for a bright reveal, kraft outside for a natural parcel. Measure the product with its tissue and card, add 5 mm each way, and check the outside against the courier band. Brands that print the inside and add a locking lid use the ear lock mailer boxes with a printed lid.

Send the two artworks as separate files, each on its own dieline, and the proof shows them together. Email the sizes, liner colours, quantity and any card slot or tear strip, and a custom quote comes back within one working day, followed by a free design proof. Mailers are made in 4 to 7 working days once approved and delivered flat, free and tracked, on the UK mainland in 2 to 3 days. Boxes that arrive crushed or misprinted are reprinted or refunded when reported within 10 days.