Four signatures, one carton. Marketing approved the PDF, quality approved the press proof, purchasing approved the first-article sample, and the limit sample hangs at goods-in. That is what print approval for packaging looks like when it works.

Usually it looks different: an email saying “fine by us” under a screenshot, and three months later the question why the brown on the second pallet is not the brown on the first. The reason is not carelessness. It is the assumption that one approval approves everything. None does. Each stage says something different, and whoever knows the stages knows which signature is worth something in a complaint and which is not.

We describe the chain from the side of the plant that runs through it: what the PDF binds, what only the press proof shows, what first-article and limit samples are for, who signs when, and what still holds on a repeat order. Plus the case almost every enquiry misses: an item with two printed surfaces.

What does the approval PDF bind, and what does it not?

The approval PDF binds position, size and content; it does not bind colour or shade. That is not a printer’s quibble but physics: a PDF describes colours as numbers, and what those numbers become on kraft board depends on paper, ink film, process and the press on the day. So whoever checks a mandatory mark in the right place, the producer details, the cut marks and the text on the PDF is checking exactly what the PDF is for. Whoever judges colour on the PDF is judging their monitor.

In practice, for a chain with 40 sites approving its meal box, the PDF approval is the moment at which typos, wrong allergen notes, forgotten identification elements and a shifted logo become final. After that the plant prints what was approved, and a text error is no longer a defect from that signature onwards but your artwork. What goes wrong inside the file itself, from screens on kraft to type on the crease, is in our guide to getting the artwork right for printed food packaging; this guide is about which document catches which error.

Soft proof, hard proof or press proof: which stage is colour-binding?

Only the hard proof and the press proof are colour-binding. The soft proof shows position and content, the hard proof colour to a standard, the press proof colour on your material. The soft proof is the simulation on a calibrated monitor: software converts the file through a colour profile and shows what to expect. Good for layout and text, unsuitable for critical tones, never the basis of a complaint. The hard proof, in UK printing often called a contract proof, is a print to a standard with a control strip along its edge: a row of colour patches whose measured values are recorded. That strip turns the proof into a reference against which production is later measured, and it is the document that counts in a complaint. Without the strip the print-out is a pretty sheet.

The press proof, a wet proof on the production press, is the third stage and the only one that happens on your real material. It becomes worthwhile where the hard proof reaches its limit: the common standard profiles describe white coated and uncoated papers; for brown kraft there is no such profile, and a hard proof on white proofing paper can only approximate kraft. The same applies to spot colours, fine screens and highly absorbent papers. Our product page for paper cups carries the lines on print process and print colours: offset printing, with CMYK and Pantone colour printing available. Those two lines decide the stage: a CMYK design on white cup board is well covered by a hard proof; a Pantone spot colour as brand colour on the same cup is a case for the press proof, because the spot colour only comes into being on the press. For custom printed paper cups we therefore ask before the proof whether the brand colour is a spot colour; the answer decides which document you sign.

This is where our own interest belongs openly on the table. Without a press proof we print faster, and a press proof costs press time and material that show up in the lead time. We still offer it where it proves something and advise against it where it proves nothing: a press proof for a single-colour black wordmark on white board is time without insight. A press proof for a brand brown on natural kraft is the only way to see, before 100,000 pieces, what you will get.

White sample and first-article sample: function before colour

The white sample tests construction and dimensions without print; the first-article sample tests everything together, once, before the run. The white sample comes off the die, unprinted, and answers questions no proof can answer: does the tab close, does the lid fit the rim, does the box stand on the shelf, does the sleeve carry its contents? Whoever skips the white sample learns those answers from the first pallet. The first-article sample is the term the automotive industry knows as first-article inspection: a sample from production material, production tooling and the production process, checked against every line of the specification and released with a report. It happens once; after that goods-in samples. In packaging it is sometimes called the approval sample or, borrowed from sourcing, the golden sample. The name does not matter, the property does: it must come off the machine that will later run the order, not from the sample shop.

From production we see the most common short-circuit here: the customer receives a hand-made sample from the sample shop, released as the “first article”, and is surprised that the run breaks differently along the creases. The sample shop cuts with a plotter; the run cuts with the die. Always ask where a first-article sample was made. A sample from the production die shows the nicks, the small holding points along the edge; a plotter sample has none.

Limit sample: the document goods-in needs

The limit sample shows how far the run may deviate from the first article and still be accepted; without it, goods-in decides by taste. It is approved by quality, in two copies, one at the manufacturer and one with you, and it carries date, item, version and signature. Typical limits for printed packaging: the lightest and darkest accepted shade of the brand colour, the largest tolerated register shift between two colours, the weakest accepted crease, the thinnest accepted ink film on kraft. What the specification says in numbers, the limit sample shows in the hand, and the two belong together: the number is for the dispute, the sample is for the dock. How tolerances get into a specification at all and what goods-in may measure is in our guide to packaging specifications; the limit sample is the part of it that does not fit into numbers.

A note on shelf life: a limit sample on kraft yellows and fades at a window. After a year it no longer shows the agreed limit but a new one. Keep it in the dark and renew it with every repeat order that triggered a new approval.

Who signs what: four approvals in one chain

Four approvals, four responsibilities, and none can stand in for another. Content approval on the PDF belongs to marketing and, where mandatory information is involved, to legal or quality: text, logos, identification elements, allergens. Colour approval on hard proof or press proof belongs to quality or the brand owner, with the control strip or the proof sheet as evidence. Function approval on white sample and first article belongs to purchasing together with the site or kitchen that has to work with the pack; it checks dimensions, fit and handling against the specification. Production release belongs to the manufacturer itself: only once its production has confirmed the first article against the limit sample does the press run. This order is not bureaucracy but the answer to the question of who is liable for which deviation. A typo sits with content approval. A wrong brown sits with colour approval if a press proof was signed, and with the customer if only a screenshot exists. A box that does not close sits with function approval. The chain with 40 sites used to have an email saying “fine by us”. Now it has four signatures, and since the second year no argument about brown.

Repeat order: does the old approval still hold?

It holds as long as artwork, material, process and manufacturer are unchanged; if one of them changes, the affected stage needs a new signature. A repeat of the same item therefore does not run through the whole chain again but against limit sample and specification. Four events trigger a new approval: a change of paper or coating at the manufacturer, even if it only concerns the paper mill; a change to the artwork, be it a new identification element required on packs sold into the EU since 12 August 2026 or a new UK mandatory mark; a change of print process, say from flexo to offset at larger volume; and a change of plant. For the first two one stage usually suffices; for the last two the chain starts again, because another plant and another process deliver another brown.

The duty to report a change lies with the manufacturer, and it must be in the contract. A plant that quietly changes the paper and releases against the old limit sample has formally done nothing wrong if nobody agreed the notification. That one line in the supply agreement is worth more than any press proof.

Approval checklist before the first print run

Nine questions whose answers should be fixed before the proof, so that the chain does not start at the press.

  • Which process prints the item, and what does that mean for spot colours: flexo with a limited number of colours or offset with CMYK and Pantone?
  • Which colour stage does the manufacturer supply: soft proof, hard proof with control strip or press proof on the actual material, and what of that sits inside the lead time?
  • Is the brand colour a spot colour, and is it printed on brown kraft or white board?
  • Does the first-article sample come off the production die and the production press, or from the sample shop?
  • Does the manufacturer supply a limit sample in two copies, with date, item and version?
  • Who signs the four approvals on your side, and who on the manufacturer’s?
  • Is there a second printed surface on the item that needs an approval of its own?
  • Which change triggers a notification by the manufacturer, and how long before printing?
  • Where are proof, press sheet and limit sample kept, and who renews them after a change?

The seventh question is the one most enquiries walk past, and it comes from an unassuming product group. Our product page for paper straws says, in the line on wrapper printing, that custom printing on the individual paper wrapper can be evaluated according to artwork and production specification, and in the line on print colours that up to three-colour custom flexographic printing is available. Those are two printed surfaces with two processes and two materials: the straw itself in flexo with at most three colours, the paper wrapper as a surface of its own with its own approval. Whoever approves only the straw for custom printed paper straws and lets the wrapper “run along” has never seen the second surface before it lies in the carton in 50,000 copies. The same goes for cup and lid, box and sleeve, bag and label. Two surfaces, two chains.

What you have read is the practice of a manufacturer that collects the signatures; whether an approval holds in a dispute is decided by your contract and your legal team, not by the printer. But the experience is unambiguous: whoever has four documents rarely argues. Whoever has one email argues about brown.

In short

  • The approval PDF is binding for position, size and content, not for colour; a soft proof on a monitor is never colour-binding.
  • Colour-binding are only the hard proof with a control strip, whose measured values are recorded and which is the reference in a complaint, and the press proof on the actual material.
  • There is no standard proofing profile for brown kraft; brand colours as Pantone spot colours on kraft are secured with a press proof, CMYK on white board with a hard proof.
  • The first-article sample is fully checked once against the specification before the run and must come from production tooling and press; the limit sample shows the permitted deviation and sits at goods-in.
  • Four approvals have four owners: content (marketing, legal), colour (quality), function (purchasing with the site), production release (manufacturer); a repeat order runs against limit sample and specification until material, artwork, process or plant changes.
  • Items with two printed surfaces, such as paper straw and wrapper or cup and lid, need two separate approvals.