A packaging reprint often has nothing to do with the factory’s press. The problem starts earlier, with artwork placed on the wrong dieline, text that runs into a fold, or a brand colour that was approved on an office printer and then printed on brown board.
This guide is for brand owners, designers and buyers sending packaging artwork to a factory in Asia. It explains what the dieline is and how to use it, how to prepare files the factory can print without redrawing, how spot and process colour differ, which proof to ask for at each stage, and which international print standards a factory may refer to.
💬 Sending packaging artwork to a new factory? We check the dieline, files and colour references with the factory before anything is printed. Tell us about your packaging.
The dieline comes from the factory, not the designer
Ask the factory for the dieline of the exact box, bag or label it will make, and place your artwork on that file; do not design on a template from the internet.
A dieline is the flat drawing of the package: where it is cut, where it folds and where it is glued. Two boxes of the same outer size can have different dielines, because each factory’s cutting dies, board thickness and glue flaps differ. Artwork placed on someone else’s template is likely to land a few millimetres off on the real box.
A usable dieline file has its information on separate layers, clearly named:
| Layer or line | What it shows | Why it matters |
|---|---|---|
| Cut line | Where the die cuts the sheet | Artwork outside it is cut away |
| Crease or fold line | Where the board folds | Text across a fold cracks or reads badly |
| Bleed | Print area extended beyond the cut | Prevents white edges if cutting shifts slightly |
| Safe zone | Inner margin inside the cut and folds | Keeps text and logos away from edges |
| Glue area | Where flaps are glued | Ink and coatings here can stop the glue holding |
| Windows and perforations | Openings and tear lines | Artwork must avoid or follow them |
| Finishing areas | Foil, emboss, spot coating | Each finish usually needs its own layer and die |
Ask the factory how much bleed and safe margin it wants, and whether glue areas must be left unprinted. Keep the dieline layer in the file you send back, but set it so it does not print.
For corrugated mailers, the box is usually identified by a style code from the International Fibreboard Case Code; our guide to mailer boxes for e-commerce explains it. For rigid boxes and folding cartons, see custom printed boxes.
Prepare files the factory can print without redrawing
Send editable vector artwork on the factory’s dieline, with fonts outlined or supplied, images linked at the resolution the factory asks for, and every colour named.
When a factory has to redraw or fix a file, it can change details without telling you. A clean file avoids that. Before sending artwork:
- Use the factory’s dieline at full scale, and do not move or redraw its lines.
- Outline fonts or supply them. A missing font is replaced by another, and small text changes shape.
- Embed or link images at the resolution the factory specifies. Ask before you send; a picture taken from a website is rarely enough for print.
- Name every colour. State which colours are spot colours and which are made from process inks, and remove unused colours from the swatch list.
- Put finishes on separate layers, with each layer named: foil, emboss, spot UV, white ink, varnish-free areas.
- Mark barcodes, and check their size, quiet zone and colour contrast. Our article on packaging for online marketplaces explains who allocates the GTIN.
- Send a PDF view alongside the working file so the factory can see what you intend.
Write the text on the pack in the file, not as a separate note. If the pack needs regulatory text in more than one language, have the text checked by someone who reads that language before the proof, not after.
White ink and special substrates
On kraft board, metallic film or clear windows, colours print over the substrate rather than over white. If you want a colour to look as it does on white paper, the factory may need to print a white underlay first. Put the white on its own layer and ask the factory to confirm where it will print.
Spot colour or process colour
Process colour builds an image from cyan, magenta, yellow and black dots; a spot colour is a premixed ink. Use spot colour where a brand colour must stay consistent, and process colour for images.
| Process colour (CMYK) | Spot colour | |
|---|---|---|
| How it is printed | Four inks combined in dots | One premixed ink per colour |
| Best for | Photographs, gradients, many colours | Logos, flat brand colours, large solid areas |
| Consistency between runs | Varies with press, paper and ink balance | Usually steadier, if the same ink formula is used |
| Cost driver | Fixed set of four plates or units | Each spot colour adds a plate or unit |
| Range | Some bright or saturated colours cannot be reached | Wide range, including colours outside CMYK |
| Metallic and fluorescent | Not possible with standard process inks | Possible with special inks |
Brand colours are usually specified by a number from a published colour-matching guide. That number tells the factory which ink to mix, but the printed result still depends on the paper or board. A colour printed on coated white board, uncoated paper and brown kraft will look different even with the same ink. Ask the factory for an ink drawdown on the actual material.
Do not approve colour on a screen or an office printer. Monitors and desktop printers are not calibrated to the press, and the same file can look quite different on each.
Printing method changes what you can expect
Offset, flexographic and digital printing each have their own process standards and their own limits on fine detail and colour, so ask which method the factory will use before you finalise artwork.
- Offset lithography is common for folding cartons and the printed wrap of rigid boxes. It reproduces fine text, images and gradients well.
- Flexography is common for corrugated board, paper bags, labels and flexible packaging. It suits solid colours and line art; very fine detail and smooth gradients are harder.
- Digital printing suits short runs, many versions and prototypes. Colour may vary between digital and the press used for volume production.
International standards set process parameters for these methods. ISO 12647-2:2013 covers offset lithographic processes, ISO 12647-6:2020 covers flexographic printing, and ISO 12647-7:2016 covers proofing processes working directly from digital data. ISO’s catalogue showed parts 2 and 6 at the “to be revised” stage when we checked, so a newer edition may follow. Ask the factory which standard or print condition it prints to, and make sure your proof is made for the same condition.
Which proof at which stage
Use a screen proof to check content, a calibrated contract proof to set colour expectations, and a press proof or on-press sample on the real material to approve colour for volume.
| Proof type | What it shows | What you can approve on it |
|---|---|---|
| PDF or screen proof | Layout, text and position on the dieline | Content, spelling, barcode placement, layer set-up |
| Digital contract proof | Colour simulated on a calibrated proofing system | Colour direction for process colour, if made to the right print condition |
| Ink drawdown | Spot ink spread on the actual material | Spot colour on that paper or board |
| Structural or white sample | Unprinted package | Size, fit, folding, opening |
| Press proof or pre-production sample | Printed on the production process and material | Colour, finishes, registration, assembly |
| On-press approval | Sheets checked during the run | Final colour match against the approved standard |
Our general article on sample approval stages explains how to record each approval in writing.
View samples under the same light
Colour judged under shop lighting, office lighting and daylight can look different. ISO 3664:2025 sets viewing conditions for graphic technology and photography. Ask the factory whether it compares samples in a viewing booth built to that standard, and use similar lighting when you check them yourself.
💬 Want a second pair of eyes on proofs before the factory prints? We compare proofs and press samples with the approved standard and report back with photos. Send us your artwork.
Record the approved standard
Keep a signed and dated colour standard, the final artwork file and the dieline version together, and refer to them on every reorder.
Colour drift between orders often starts when the reference is lost. For each package keep:
- the final artwork file and its version number, with the dieline version it was built on
- the approved press sample or colour standard, signed and dated, with one copy at the factory and one with you
- the spot ink references and the material specification
- notes on any tolerance agreed with the factory for colour and registration
When something changes, such as a new board supplier, a different press or a new factory, make a new proof against the old standard rather than assuming the result will match. At pre-shipment inspection, the inspector compares production against this standard.
If your packaging carries environmental claims or certification logos, the logo artwork itself may come with usage rules; our guide to recycled and FSC claims by market explains how to check them.
Frequently asked questions
1. Can I use a free dieline template from the internet?
Use it only for early concept work. The final artwork must sit on the dieline of the factory that cuts the package, because dies, board thickness and flaps differ between factories.
2. Why does my brand colour look different on kraft paper?
Kraft is brown, and the ink prints over that colour. Use a white underlay, a white or coated material, or approve a separate colour standard for kraft.
3. Is a digital proof enough to approve colour?
It can set colour expectations if it is made to the factory’s print condition. For spot colours and special materials, approve an ink drawdown or press sample on the real material.
4. How many spot colours can I use?
It depends on the press and budget. Each spot colour adds a plate or print unit. Ask the factory how many colours its line prints in one pass.
5. What should I keep for reorders?
Keep the final artwork, the dieline version, spot ink references and a signed press sample. Refer to them on every reorder so the factory matches the same standard.
Summary
Design on the factory’s dieline, send clean files with every colour named, approve colour on the real material and keep the approved standard for the next order. A missing or wrong reference is where many colour problems start.
Sunsho Trade is a trading company, not a factory. For packaging projects we find the factory in Asia that fits the job, check dielines and artwork with it, follow proofs and samples, and inspect production against the approved standard.
💬 Ready to send your packaging to print? See our custom packaging service, or send us your artwork and dieline and we will check them with the factory.
Sources
Checked on 26 October 2026.
- ISO, ICS 37.100.01 Graphic technology in general, catalogue listing for ISO 3664:2025, ISO 12647-2:2013, ISO 12647-6:2020 and ISO 12647-7:2016 with their stage codes: https://www.iso.org/ics/37.100.01/x/
- ISO 3664:2025, Graphic technology and photography, Viewing conditions: https://www.iso.org/standard/83759.html
- ISO 12647-2:2013, Graphic technology, Process control, Part 2: Offset lithographic processes: https://www.iso.org/standard/57833.html