A keyline is the flat blueprint of your box. Unfold a carton, lay it out on a table, and trace every edge and every crease: that drawing, produced to scale with each line type labelled, is the keyline. Your designer works on top of it, and the cutting die is made from it. Getting it right is the difference between artwork that lands where you expected and artwork that gets trimmed off.
What the lines mean
| Line | Usual convention | What it tells the designer |
|---|---|---|
| Cut line | Solid | The knife goes here. Nothing you need to see should touch it. |
| Crease or fold line | Dashed | The board bends here. Text crossing a crease will crack or distort. |
| Perforation | Dotted or dot-dash | A tear-open feature, usually a lid or a dispenser opening. |
| Glue area | Shaded or hatched | Adhesive lands here, so it must stay free of ink and varnish. |
| Bleed | Outer boundary beyond the cut | Extend background artwork to here so no white edge appears after trimming. |
| Safety margin | Inner boundary inside the cut | Keep logos, legal text and barcodes inside this line. |
Keyline or dieline: is there a difference
In day to day use, no. Some studios reserve "keyline" for the artwork-side template and "dieline" for the file the die maker cuts from, but they describe the same geometry and most suppliers will understand either word. What matters more is that the line layer is separate and non-printing. A keyline accidentally left on a printing layer is one of the most common reasons a proof comes back with thin black lines running down a panel.
Working on a keyline without breaking it
- Never resize or redraw the template. If it does not fit your artwork, the artwork changes, not the structure.
- Check panel orientation. On a folding carton some panels are upside down in the flat, which is correct, and rotating them to look right in the flat file makes them wrong on the finished box.
- Keep barcodes off creases and out of glue areas, and give them a quiet background.
- Extend background colour and images to the bleed boundary, not to the cut line.
- Pull all critical content inside the safety margin, then look at the flat and ask what happens to it after folding.
Why this matters commercially
The keyline is where a custom size stops being expensive. Because the cutting die and the plates are included with your order at iBox Factory, along with design support and a digital proof before anything prints, a carton drawn to your actual product dimensions costs the same to tool as one forced into a near-standard size. The practical advice is simple: get the keyline before you finish the artwork, not after.
Ordering and turnaround
Minimum order is 100 boxes. Price starts from about $0.48 per unit at bulk volumes and is confirmed on your written quote once structure, board, print coverage and finishing are set. Production runs from two plants, West Chicago in the US and Guangzhou in China, in three lanes: rush is expedited production plus air freight and carries a premium of about 7 to 25% depending on the job, standard moves by air, cost saver moves by sea. The floor is from about 7 business days, plus 2 to 5 for delivery, and specialty imported items can run up to about 12 weeks. Proof approval sits on your side of that clock, so a fast approval is the cheapest way to protect a launch date.
If you are at the very start of the process, how to order packaging for the first time walks the whole sequence. If you are about to commit to a production run, how to test packaging before a big run covers what to check on the sample. Send your product dimensions through the quote form and ask for the keyline up front so your designer can start while the pricing is being finalised.
