Artwork delays are the silent killer of packaging launch timelines. The box is designed, samples are approved, the order is placed — then the artwork file isn't print-ready, the pre-press check flags problems, and the lead time extends by two or three weeks while revisions happen.
Having seen this play out dozens of times, here's what actually needs to be in order before you send a print file to a packaging supplier.
The Dieline (Cutter Guide)
Every printed packaging job starts with a dieline — the technical template that shows the exact flat layout of the box, including all fold lines, cut lines, and the bleed area. The dieline is structural information from the packaging manufacturer; it's not something your designer can create independently.
Before any artwork development starts, get the confirmed dieline from your packaging supplier. This requires having confirmed your box dimensions, style and board grade. Changes to any of these after artwork development starts will require artwork to be revised.
The dieline should be provided as a vector file (PDF, AI or EPS). Lock it on a separate layer in your design application — it should never be modified by the designer.
Colour and File Format Requirements
Colour mode: printing is CMYK (four-colour process). Artwork submitted in RGB will be converted, and the conversion will change how colours appear. Design and supply artwork in CMYK from the start.
Special colours: if your brand uses a Pantone (spot) colour, confirm with your supplier whether they can match it. Flexographic printers can usually accommodate spot colours; digital printers typically convert everything to CMYK. If a specific Pantone is critical, it must be specified explicitly in the brief — not just visually approximated in the file.
File format: ask your supplier what they require. Typically PDF/X-1a or PDF/X-4 for press-ready files. Packaged InDesign or Illustrator files are usually acceptable as an alternative. Never supply PSDs or Word files.
Resolution: any rasterised elements (photographs, textures) should be 300dpi minimum at final printed size. 72dpi screen-resolution images look sharp on screen but print soft and pixellated.
Bleed and Safe Zone
Bleed is the extension of the artwork beyond the cut line — typically 3mm for corrugated packaging, though some substrates require more. This exists because cutting is not perfectly precise; without bleed, small misregistrations cause white edges.
Safe zone (or live area) is the area inset from the cut line within which all critical information — text, logos, barcodes — should sit. Important content too close to the edge risks being cut off. Typically 5mm minimum from the cut line.
Both bleed and safe zone guidelines should be shown on the dieline your supplier provides.
Barcodes
Barcodes are a common source of pre-press problems. Common issues:
- Bar/space colour combination that doesn't scan reliably (always supply as black bars on white background unless the substrate forces otherwise, then verify with the supplier)
- Barcode too small — minimum sizes are specified by GS1 for EAN/UPC codes
- Barcode placed in the bleed area or too close to the edge
- Incorrect or unverified barcode data
If your barcode has been generated in-house, run it through a barcode verification check before submitting artwork. A failed barcode causes a retail listing problem that's expensive to fix after production.
Pre-Press Checks
A reputable packaging supplier will run pre-press checks on any file before sending to plate or print. They will flag problems to you. This is not a failsafe — it catches technical issues but doesn't catch incorrect content.
Before submitting, check: product name is correct, weight or volume declarations are accurate, all regulatory text is present and correct, contact details are current, and all content is legally approved if you're in a regulated category.
The two weeks you lose to a pre-press revision cycle is almost always cheaper than the cost of reprinting after a content error.