Quick answer
To specify an inner box or insert for print, give the printer the product’s exact measurements and weight, the material and thickness, cut-out sizes with clearance, which sides are printed and in how many colours, any finishes, the quantity and the dieline. Then ask for a physical sample and test it with the real product before approving the run.
The outer box gets all the attention, but the insert is what the customer touches first after opening it. It holds the product in place, protects it through the post, and decides whether the unboxing feels considered or improvised. It is also the part of packaging where vague instructions cost the most. A cut-out two millimetres too small means a pallet of inserts that will not take your product. A note saying “nice card insert, white” gets you whatever the printer thinks that means.
Types of inner box and insert
| Type | What it is | Good for |
|---|---|---|
| Die-cut card tray | Folding boxboard with holes cut to the product shape | Bottles, jars, small cosmetics, gift sets |
| Corrugated insert | Fluted board, folded or slotted to form compartments | Heavier items, glass, multi-packs |
| Moulded pulp tray | Pressed recycled fibre shaped to the product | Electronics, fragile items, eco-led brands |
| Inner sleeve or box | A second printed box inside the mailer or outer | Premium unboxing, protecting the retail pack |
| Printed insert card | A flat card with a message, instructions or offer | Thank-you notes, care guides, reorder prompts |
What to put in the specification
Printers price and make exactly what you specify. These are the lines that matter:
- Product dimensions and weight. Measure at the widest points, with callipers if you can, and include caps, pumps and labels.
- Material and thickness. Board type and weight, or flute type for corrugated. If unsure, describe the product and ask the printer to recommend.
- Cut-out sizes and clearance. State the hole size you want, not just the product size, so there is no doubt about tolerance.
- Print sides. Inside only, outside only, both, or unprinted. Each side printed adds cost.
- Colours. Full colour, a single spot colour, or a plain kraft or white board.
- Finishes. Matt or gloss lamination, spot UV, foil. Our guide to print finishes explains what each does.
- Quantity and delivery. Including whether the inserts arrive flat or assembled.
- The dieline. Your printer’s template for the exact insert, or a request for them to create one.
Getting the measurements right
Most insert problems trace back to measurement. Measure several units of your product, because they vary. Glass bottles in particular can differ by a millimetre or more from one batch to the next. Measure with any labels or shrink wraps fitted. Think about how the customer will lift the product out: a finger notch or ribbon pull may be needed for a tight fit.
Give the printer the hole size you want. “Product is 52mm wide; please cut a 54mm hole” leaves no room for interpretation. Then confirm it on a sample.
Designing the artwork
Insert artwork goes on the printer’s dieline, with the cut-outs, folds and glue areas marked. Keep text and important graphics away from the cut lines and folds, and include bleed on every printed edge. If the insert is printed inside a box that is printed outside, both pieces need to work together when the lid is open: same colours, same type, a clear sense of which piece the customer sees first.
Our guide to print-ready artwork covers bleed, colour modes and file formats, and if a printer has bounced your files before, our post on printer-rejected artwork explains the usual reasons.
Sustainability choices
Inserts are often the part of the pack that customers struggle to recycle. Plastic foam and mixed-material inserts are the usual problem. Paper-based inserts in a single material are easier, and certified board from responsibly managed forests is widely available; the Forest Stewardship Council explains its certification. If you add recycling information to the pack, the OPRL labelling scheme is widely used in the UK. Growing businesses should also check whether they have duties under the government’s packaging producer responsibility rules.
Sample, test, then approve
Always ask for a physical sample, ideally a plain white one cut on the real die before the full printed run. Test it properly:
- Fit the real product, several units of it.
- Shake the closed box; nothing should rattle or shift.
- Drop it from table height onto a hard floor, packed as it will be shipped.
- Unbox it as a customer would. Can you get the product out without tearing anything?
Fix problems at this stage. Changing a die after a full run is far more expensive than changing it after a sample.
A worked example: a candle and diffuser gift set
A home fragrance brand wanted a gift box holding one candle jar and one reed diffuser bottle. The first quote request said “white card insert to hold two items”. The printer quoted a thin board with generic round holes, and the sample let the diffuser bottle lean and knock against the jar. The revised specification gave the exact diameters of both items at their widest points, a 2mm clearance for each hole, a heavier board, a raised platform so both products sat at the same height when the lid lifted, a finger notch beside each item, and printing on the top face only in the brand’s single colour. The second sample held both items firmly, survived a drop test, and cost little more than the first, because the unprinted underside and the single colour offset the heavier board.
Common mistakes
- Measuring one product unit and assuming all are identical.
- Specifying “card insert” with no board type or thickness.
- Forgetting the depth of the insert against the inside height of the box.
- Printing both sides when only one is ever seen.
- Approving digital proofs only, without a physical sample.
Getting it designed
Our packaging design is £99 one-off for the artwork, built to your printer’s dieline, and it can cover the outer box, the insert and the insert card as a matching set. Our guide to packaging design for small brands covers the wider pack, and all our prices are on the pricing page. Printing is quoted separately by your printer.
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Frequently asked questions
What is a packaging insert? +
An insert is the part inside a box that holds and protects the product: a card tray with cut-outs, a folded divider, a moulded pulp tray or a foam piece. It stops the product moving in transit and controls what the customer sees first when they open the box. A printed insert card with a message is also sometimes called an insert.
What material is best for box inserts? +
For light products, folding boxboard with die-cut holes is usually enough. Heavier or fragile products need corrugated board, moulded pulp or a fitted foam, depending on weight and how much protection is needed. Paper-based options are easier for customers to recycle. Ask your printer for samples and test with the real product.
How accurate do insert cut-outs need to be? +
Measure the product precisely, at its widest points, and give the printer those sizes with your required clearance. Too tight and the product will not go in; too loose and it rattles. A millimetre or two of clearance is common for rigid products, but always confirm on a physical sample before the full run.
Do I need a separate design for the inner box? +
Yes. The inner box or insert has its own dieline, its own print sides and its own finishes, so it needs its own artwork file. It should feel like part of the same pack, using the same colours and type, but it is a separate piece for the printer to make and price.
