A dieline is the flat template of your packaging — the shape the box is before it is folded. It is the single most important file in the whole process: everything you approved visually happens inside it. You do not need design software skills to review one, just a checklist.
The line language
- Solid lines = cut. The knife follows these.
- Dashed or dotted lines = fold (crease). The box bends here, not cuts.
- Solid red/magenta lines on many dielines = bleed boundary or safety margin.
What to actually check
1. Internal dimensions. Measure the flat panels: length × width × depth should match your product plus clearance. Paper needs breathing room — 1–3 mm per side depending on product rigidity. 2. Panel orientation. Rotate the dieline in your mind: is your logo upright on the front panel when folded? Rotated artwork is the single most common dieline error. 3. Text inside the safety margin. Nothing important within ~3 mm of a cut or fold line — it gets trimmed or cracked. 4. Glue flap location. Usually hidden; make sure no design element crosses it. 5. Bleed. Any color that reaches an edge must extend 3 mm past the cut line, or white slivers appear on finished boxes.
Print the dieline. Literally print it at 100% scale, cut, and fold it from plain paper. Ten minutes of scissors tells you more than an hour of screen-staring. It is not the material feel, but it proves proportions and panel orientation.
Your factory should provide a dieline before sampling — at KUBO Paper it is part of every custom quote, free. If a supplier pushes straight to a physical sample without a dieline, that is a yellow flag: you are paying sample fees to discover sizing errors.
FAQ
Who makes the dieline — me or the factory?
The factory, always. Dielines must match their die-cutting tooling and material thickness. You supply dimensions and design; they engineer the template.
Can I change the size after the dieline is approved?
Yes, but the dieline must be revised and re-approved, and a structural sample repeated if the change is large. Size changes after die-making mean a new die — a real cost. Lock dimensions before sampling.