Printing inside your box: options, artwork and pitfalls

Most custom boxes can be printed on the inside as well as the outside: the inner liner of a corrugated mailer, the reverse of a folding carton, or the liner paper of a rigid box. It is an effective way to add a message, a pattern or a flash of brand colour that the customer only sees on opening. It works best on a white or coated inside surface, with artwork set up on the reverse of the dieline and kept clear of glue areas.

This guide explains where inside print works, how to choose the surface, and how to set up artwork so it appears where and how you expect.

Where inside print works, by box type

How inside print is produced depends on the construction, and each has its own best surface.

Mailer boxes are where inside print is most common, because the whole lid lifts to reveal the inside at once. On folding cartons the inside is seen less, but a printed inside flap or panel can carry instructions or a message. On rigid boxes, the inside lid and the insert are natural places for a pattern or a line of text.

What to print inside

Inside print works best when it is simple and deliberate. It has a single job: to reward the customer at the moment of opening.

• A message on the inside of the lid. A thank-you, a welcome or a short line of brand voice.
• An all-over pattern or brand colour. One colour across the whole inside makes a strong impression for relatively little artwork.
• Practical information. Care instructions, assembly steps or a returns note, so fewer paper inserts are needed.
• A QR code or social handle. Placed where it is seen once the product is lifted out.

Choosing the inside surface

The inside surface decides how inside print looks, so choose it with the artwork in mind.

On corrugated, the inner liner is often a plain brown test or kraft liner. Printing on it works, but colours come out darker and pale colours fade. A white inner liner gives a clean base for bright or detailed inside print. See corrugated board for liner types.

On folding cartons, the back of the board is usually uncoated, and on folding boxboard it is often cream rather than white. Ink soaks in, so inside print looks softer and dark colours look flatter. If inside print matters, specify a white or coated back; coated vs uncoated board explains the difference.

Setting up inside artwork

Inside artwork is where most avoidable problems happen. The rules are straightforward once you know them.

• Use the inside view of the dieline. The inside of the sheet is the reverse of the outside, so the dieline is mirrored: panels that sit on the left from outside sit on the right from inside. Ask for the inside view rather than flipping the outside yourself. Our guide to what a dieline is explains the layout.
• Check which way is up. Think about how the box opens. Inside-lid artwork usually needs to read upright when the lid is raised towards the customer, which is often upside down relative to the outside lid artwork.
• Keep glue areas clear. Glue flaps and glued panels need a clean surface to bond. Leave them free of ink and varnish where the dieline marks them.
• Allow for bleed and safe areas. The same rules apply inside as outside; see bleed, trim and safe areas.
• Supply it separately. Put inside and outside artwork on separate artboards or pages, clearly labelled.
• Plan around the insert. If an insert fills the base, anything printed there is hidden until the insert is removed. Design the box and the insert together.

Finish and protection inside

The inside of a box is usually left unlaminated. It is not handled in the way the outside is, and glue areas need to stay clear. On corrugated mailers, inside print is protected by the lid once closed, but heavy solid colours can rub onto light-coloured products over time, so consider a lighter design or a wrap for pale textiles.

Where the product is food, check the whole specification before designing inside print. Where unwrapped food would touch printed board, the board, ink and any coating must be suitable for that use; see our food packaging guide.

Inside print and cost

Inside print adds a second printing pass, so it adds to the cost; how much depends on the number of colours and the coverage. Our guide to what determines packaging cost explains how each option moves the price. For e-commerce brands, inside print can also replace some separate printed inserts, which is worth weighing up; our e-commerce packaging guide covers the wider unboxing picture.

Common mistakes

• Designing inside artwork on the outside dieline. The panels are mirrored inside; use the inside view.
• Inside-lid text that reads upside down. Check the orientation against how the box actually opens.
• Printing over glue areas. Ink and varnish on glue flaps weaken the bond.
• Pale inside colours on kraft liners. They darken and fade; use a white inner liner or darker colours.
• Hiding the best artwork under the insert. Plan the inside print around where the insert sits.
• Expecting outside quality on an uncoated carton back. Specify a coated or white back if inside print matters.