What to check before you approve a hoarding proof

A proof is the last moment a hoarding costs nothing to change. After it, the file goes to a large-format press, the material is cut to size, and a crew books a ladder or a hydra. Everything after approval is a reprint, not an edit.

The trouble is that a hoarding proof arrives as a small image on a screen, and almost every mistake that survives to the roadside survives because it was invisible at that size. What follows is a checking order that puts the expensive mistakes first.

1. Read the phone number out loud, digit by digit

Not "check the phone number" — read it aloud, one digit at a time, against the source you trust. The same applies to a website address, a WhatsApp number and a GST number if one appears.

This is first on the list because it is the single most common reason a hoarding is reprinted, and because familiarity is what defeats it. Your eye reads a phone number it already knows; it does not read the number that is actually printed. Have someone who does not know the number check it too.

2. Confirm the finished size against the site, not against the design

A proof is usually shown at a convenient ratio, not at the real dimensions. Look for the stated finished size in millimetres or feet and compare it to the measurement taken at the site — the frame, the wall, the gantry.

Two related things to confirm at the same time:

• The aspect ratio matches. A 20 ft × 10 ft frame given a 20 ft × 8 ft design leaves two feet of nothing, which reads as a mistake even when the print is perfect.
• The proof and the site agree on which is width. Landscape and portrait getting swapped between a brief and a survey is not rare.

3. Look at the safe area, not just the artwork

A hoarding is not flat art hanging in space. It is stretched over a frame, clamped at the edges, or wrapped around a return. Anything within roughly 75–100 mm of the trimmed edge is at risk of being eaten by the fixing, and on a frame with a folded seam that margin is larger.

Check that nothing important — a logo, the last word of a line, the edge of a face — sits in that band. Background can and should run past it. This is different from bleed, which is covered below.

4. Check the bleed exists at all

Bleed is background extended past the trim line so that a slight cutting or stretching variance does not show a white sliver at the edge. Large format generally wants more of it than paper printing does.

On a proof, bleed is often hidden. Ask for the trim marks or the working file dimensions if you cannot see it. A design that stops exactly at the trim line will, sooner or later, show the substrate at one edge.

5. Read it at the distance it will be read from

The single most useful test costs nothing: shrink the proof on your screen until it is about the size of a matchbox, stand back, and see what you can still read.

That is roughly what a driver gets. If the headline does not survive it, no amount of detail below the headline matters, because nobody reaches the detail. A hoarding read from a moving vehicle carries one idea, one identifier and one way to act — everything else is decoration.

6. Count the colours you are asking for

Large-format print is a subtractive, ink-on-substrate process, and the screen you are approving on is an emissive one. Some colours simply cannot be reproduced on flex, and the ones that suffer most are predictable:

If the brand depends on one exact colour, say so before approval and ask whether it is being matched to a reference. A colour that matters is worth a physical patch on the actual material, not a screen approval.

7. Check the contrast between text and background

Outdoor viewing is done in glare, in rain, at dusk and at night under sodium or LED light. Contrast that is comfortable on a bright monitor in a room is often not comfortable on a road.

Light grey text on white, thin type on a photograph, and text sitting over the busiest part of an image are the three that fail most often. If text sits on an image, it usually needs its own solid or heavily darkened panel behind it.

8. Look for image resolution at the real size

A photograph that looks sharp in a proof can be badly under-resolution at 20 feet. Large format tolerates far lower pixel density than paper printing does, because of viewing distance — but there is still a floor, and web-sourced images are frequently below it.

The tell on a proof is soft edges around hard objects, blocky gradients in a sky, or a fuzzy halo around a logo. If you see any of those in a small proof, they will be worse at size. Ask for the original file, or for the logo as a vector.

9. Confirm the material and the finish are what you agreed

The proof shows the artwork. It does not show what the artwork is being printed on, and that decision changes both the price and the life of the hoarding. Confirm in writing:

• the material and its weight or grade;
• whether it is front-lit or back-lit, which changes how the file is prepared;
• the finish — matt or gloss, and whether it is laminated;
• how it is finished at the edges — eyelets, welded pockets, a folded hem;
• who is mounting it, and whether the frame is being supplied.

10. Check the legal and permission text

Depending on the site and the local rules, a hoarding may need to carry specific text — a permission or licence number, an advertiser's name, a statutory disclaimer for regulated categories such as health or finance.

This is the item most often left to the last minute and then added as an afterthought in a corner, at a size nobody can read. If it must appear, it must appear legibly, and it needs a place in the layout rather than a gap.

Approve in writing, and keep what you approved

When you are satisfied, approve in writing and keep a copy of the exact file you approved. An approval that exists only as a phone call is not a record anyone can check against later, and the version that goes to press should be the version with your name on it.

If something is still open — a phone number being confirmed, a logo being found — say what is open rather than approving conditionally. A proof approved with an outstanding question is how the wrong file reaches the press.