What "good enough" means when ten thousand copies are involved.

On a short digital run, you can examine every sheet. However, on a run of ten or fifty thousand sheets, no one can check every sheet. Quality control is managed through sampling and by setting acceptable tolerances for variation. This often surprises people the first time they commission a large print job, as they expect print quality to be either right or wrong. In reality, it's a matter of how much variation is acceptable.

Knowing where those lines sit makes you a better customer. It tells you what to check upon delivery, what issues are genuinely worth raising, and what is normal behavior that a printer cannot eliminate at any cost. This guide covers both perspectives: what happens on the press, and what to do when the boxes arrive.

What gets checked during a run

Colour density

Operators pull sheets at intervals and measure ink density using an instrument rather than judging by eye. Colour can drift throughout a run due to changes in ink and water balance, as well as temperature shifts. Operators make adjustments to bring the colour back within a controlled band. Consequently, colour may vary slightly from the start to the end of a run. Two sheets pulled from opposite ends of a long run will not be laboratory-identical, and this variation is expected.

Registration

Each ink is laid down on a separate pass or unit, and they must align. Misregistration appears as colored fringing around text or a soft double edge on fine details. Tolerances are measured in fractions of a millimeter. Small deviations within tolerance are invisible at reading distance, which is the standard that matters.

Trim position

Sheets are cut from stacks, and the blade can drift slightly due to lift. This is why bleed and safe zones are necessary: the design must accommodate slight movement without losing any critical elements. A layout with text positioned just two millimetres from the trim edge will often generate complaints, even on a job that is otherwise perfectly executed.

Physical defects

Hickeys, which are small spots caused by debris on a plate or blanket, as well as scratches, ink smears, and markings on the reverse from wet ink, are all checked for. A small number of affected sheets across a large print run is normal, which is why overs are printed.

Tolerances and overs

Two common practices in the industry can mislead those who have not previously ordered large production runs.

Overs and unders. Print quantities are traditionally quoted with a tolerance, often around five percent either way on long runs. Presses are set up with waste sheets before the run stabilises, and the finished count lands near rather than exactly on the number. If you need a guaranteed minimum, say so when ordering so the run is set up to over-produce.

Acceptable variation. Colour is judged against an agreed reference, not against a memory or a screen. That reference should be a physical proof or a signed sheet from a previous run. Without one, "it looks different from what I imagined" is not a claim anyone can act on. The reasons colour moves between runs are covered in more depth under digital printing solutions.

What to check when the delivery arrives

Do this on the day it lands, not the week before the event. Most issues are fixable if raised quickly; they become unfixable once the deadline has passed.

• Count the boxes and check the quantity per box against the delivery note before signing anything
• Open a box from the middle of the pallet, not the one on top, which is the one most likely to have been checked already
• Pull sheets from the top, middle and bottom of a stack and compare them to each other and to your reference
• Check the trim by holding several copies together and looking at the edges for a consistent line
• Fold and open a folded item to check the crease sits where it should and does not crack
• Open a bound item flat and check pages are in order, right way up, and that nothing is missing
• Look at the reverse for set-off, the faint transfer of ink from the sheet above

For bound work, page order and orientation are the two faults that produce a full reprint, and they are also the two that a quick flick-through will catch in thirty seconds. Binding-specific checks follow from the method used, covered under brochure and booklet printing.

If something is wrong

Raise the issue immediately in writing, including photographs. Keep the affected stock rather than discarding it, as it will need to be inspected. Be specific about what is wrong and how many copies are affected. For instance, saying "the color is off" and "the blue on page four is visibly lighter than the signed proof across the whole run" will lead to very different conversations.

Do not distribute part of the delivery and complain about the rest. Once the material is in circulation, obtaining a reprint becomes much harder to justify and to organize.

How to reduce the risk before you print

Most quality disputes are prevented during the file and proof stages, rather than on press.

• Approve a physical proof, rather than just a screen proof, for any item where color accuracy is important.
• Ensure that critical content remains well within the safe zone, making any trim movements irrelevant.
• Sign and retain a reference sheet from the run for future reorders.
• Specify a guaranteed minimum quantity if you cannot accommodate a shortfall.
• Agree on a delivery date that allows enough time to inspect the items. If necessary, they can be reprinted.
• Nominate one person to approve the decision, as approval by committee often leads to missed deadlines.

The final point is not a technical quality issue, but it results in more late jobs than any press malfunction.

How we run and check your work

We inspect at set intervals throughout every run and retain the pulled sheets. This ensures that if any questions arise later, there is a documented record rather than relying on recollection.

Regarding quantity, we will inform you at the quoting stage whether we are working to a tolerance or a guaranteed minimum. This ensures there are no surprises upon delivery. Should you require an exact count, we will set up the run accordingly, rather than discovering a shortfall at the end.

If you are commissioning a long run for the first time and are not sure what to specify, send us the artwork and tell us the deadline and how the piece will be used. See the full range under printing services, or for time-critical work see express and fast printing. Get in touch through the contact page.

The short version

Long runs are managed through sampling and tolerances, which means slight color movement throughout a run and minor quantity variances are normal. Approval of a physical proof, maintaining a signed reference sheet, and specifying a guaranteed minimum if needed, are best practices. Upon delivery, inspect boxes from the middle of the pallet, compare the top, middle, and bottom of a stack, and check the page order on anything that is bound.

Inspect the day it arrives. Everything is negotiable then, while nothing is negotiable on the morning of the event.