Most proofing mistakes are not exotic. They are the same eight or nine things, and they get missed because they live in somebody's head instead of on a list.
Below are three short checklists: one for you before the proof goes out, one to hand your customer, and one for the moment before output. They are deliberately short — a checklist nobody finishes is a document, not a control.
1. Before the proof leaves
Run this on the file you are about to send.
[ ] The filename carries a version number that has never been used before
[ ] The version number is higher than the last one the customer saw
[ ] Anything critical sits inside the trim, with bleed where it is needed
[ ] Every page is in the file — including the back, the inside, the reverse
[ ] The customer's own details are the ones they gave you, not the ones
from the last job
[ ] Finished size is stated on the artwork, not only in the email
[ ] What changed since the last version is written down
[ ] You know who has to approve, and that they can
Download as a fillable PDFor as plain text
Two of those are worth arguing for.
The version number that has never been used before is the single cheapest defence against the wrong-version reprint. Re-exporting over v2 because "it's basically the same" is how two different files end up with one name — the mechanics of which are in our guide on not printing the wrong version.
Knowing who has to approve costs one question at the start and saves the round where the person who replied turns out not to have been the decision-maker.
2. What to ask the customer to check
Customers proofread. They do not check production things, because nobody has ever told them those were theirs to check. Paste this into the covering message and they will.
Please check:
[ ] Spelling of names, especially people and places
[ ] Prices, dates and times
[ ] Phone number, web address, opening hours — read them out loud
[ ] Anything legal or required: registration numbers, small print, logos
you are obliged to carry
[ ] That nothing important is close to the edge
[ ] Every page, including the back
Then reply with either:
APPROVED v2 — and we go to production as it is
CHANGES — with what needs to move
Download as a fillable PDFor as plain text
"Read them out loud" is not a joke. Phone numbers and web addresses are the details the eye slides over and the mouth catches.
Asking for the version number in the approval turns a vague yes into a fact you can act on later. Copy-and-paste versions of the whole message are in our artwork approval email templates.
3. Before it goes to press
The last gate, run at the moment of output.
[ ] The file on the press is the exact file that was approved
[ ] The approval names that version, in writing, from the person entitled
to give it
[ ] No change has been made since the approval — not even a small one
[ ] If a change was made, there is a newer approval covering it
[ ] Multi-page work: the customer saw the pages, not only the first one
[ ] Colour expectations are on record, especially if only screen-approved
[ ] Quantity, stock and finish match the order, not the last job
Download as a fillable PDFor as plain text
The third and fourth lines are the ones that catch experienced shops. A correction made after the yes is usually right, usually small, and completely unapproved — which makes it the most dangerous kind of change in the building.
The prepress checklist, and where it differs from this one
Everything above is about agreement: what the customer was asked, what they said, and against which file. A prepress checklist is about the file itself, and it is run by you, on the artwork, before output. The two are separate gates and both get skipped for the same reason — they live in somebody's head.
PREPRESS / PRINT READY
[ ] Correct page size and orientation, with bleed where it is needed
[ ] Critical content inside the safe area, nothing touching the trim
[ ] Colour space right for the process: CMYK or spot, not stray RGB
[ ] Spot colours named consistently, and only the ones you intend
[ ] Images at adequate effective resolution at final size
[ ] Fonts embedded or outlined
[ ] Overprint and knockout behave as intended, especially white
[ ] Black text is a single black, not a four-colour build
[ ] Page count and imposition match the finished product
[ ] Finished size and quantity match the order, not the last job
Download as a fillable PDFor as plain text
Two of these are the ones that survive a rushed afternoon and still cause trouble: effective resolution at final size — an image can be 300 dpi and still be a poster scaled 400% — and white overprint, which looks correct on screen right up until it disappears on press.
The first of those is a measurement rather than a judgement, so it is worth measuring. Our PDF dpi checker reads the effective resolution of every image inside a PDF and names the page each soft one is on; the image resolution checker does the same for a single picture and says how large it can be printed. Both read the file in your browser, and neither uploads it.
A print-ready file that nobody approved is as useless as an approved file that will not print. Run both lists.
Where the list stops helping
A checklist is a control that depends on a person running it, and the two items above that matter most — the file on the press is the file that was approved, and the approval names that version — are the ones a person cannot verify from an inbox. Three rounds in, a thread contains three PDFs and a "looks good" that points at whichever one was open.
That is the part worth moving out of memory and into the system.
Our own tool, so read accordingly: Proofavo keeps one current version, records the approval against that exact immutable file, and produces a downloadable record naming the version, the person and the time, with a SHA-256 fingerprint of the approved artwork. A proof with an open note cannot be approved until the note is settled, and on a multi-page proof the approval dialog states how many pages have actually been opened — which is checklist item six, enforced rather than remembered.
You can run the loop yourself in the live demo: no sign-up, and the approval at the end produces a real record.