File prep for large format: resolution, bleed and artwork checks
Check size, resolution, bleed, colour and fonts before sending artwork for a banner, poster or booth graphic.
Work at final size, or at a clean fraction of it
The single most useful habit in wide-format artwork is building the document at the finished size, or at an exact fraction like a quarter or a tenth, rather than at an arbitrary size you intend to scale later. It makes every other decision checkable: text size is real text size, margins are real margins, and resolution means something.
If the piece is genuinely enormous, a 1:10 document is easier to handle and scales cleanly. What causes trouble is a file built at some incidental size that has to be scaled by an odd factor, because every measurement then has to be recalculated and small errors compound.
Resolution is measured at the size it prints, not the size it was made
A raster image has a fixed number of pixels. Stretching it does not create detail, it just spreads the same pixels across more inches. That is why a logo that looks perfect on a website can look soft on a 3-foot banner even though nothing about the file changed.
The useful resolution depends on viewing distance, image detail and output process. Around 150 pixels per inch at final size can be a starting point to discuss. A 1,200-pixel image gives 8 inches at 150 ppi, or 48 inches at 25 ppi; the latter may show visible pixels at close range. Confirm the target for your job.
Vector artwork sidesteps the problem entirely because it is drawn from mathematics rather than pixels, and it scales to any size without loss. Logos, type and flat graphic shapes should be vector wherever the original exists.
Bleed, and the material that disappears into a hem
Bleed extends artwork beyond the trim to allow for cutting variation. An eighth of an inch is common for small commercial print, but the correct allowance depends on the product and finishing. Ask for the layout requirements before preparing a banner, pocket or wrapped canvas.
Hems, pole pockets and canvas wraps each need finishing allowances. Their size depends on the construction and hardware. Extend backgrounds as specified and keep logos, faces and text within the agreed visible area; use the template for the actual product.
Colour: what will and will not match
Screens emit light and printers reflect it, so a colour that glows on a monitor may look flat on a matte vinyl. That is physics, not a printing error. The colours most affected are saturated blues, bright oranges and any neon.
The practical answer is to specify brand colours as named spot values rather than eyeballing them, and to say up front if a specific colour has to match something already in the field, such as an existing sign or a vehicle. Discuss a physical proof on a representative material when colour is critical, and agree how it will be evaluated.
It is also worth knowing that the same file printed on gloss vinyl, matte fabric and corrugated plastic will not look identical on all three. Different substrates absorb ink differently. If a set has to match across materials, say so before the job runs.
Fonts, layers and the files nobody can open
Send a PDF unless you have been asked for something else. Outline the type or embed the fonts, because a missing font substitutes silently and the first anybody notices is when the proof comes back in the wrong typeface.
Use the PDF preset requested by the print provider. Some workflows accept live transparency in PDF/X-4; others require flattening. Do not flatten indiscriminately. Package linked images and fonts with native files, or export a self-contained PDF and check it before sending.
A short checklist
Use final size or a clearly stated scale. Confirm raster resolution at that size. Keep logos and type in vector where possible. Follow the product template for bleed, pockets and wraps. Embed fonts and images in the PDF, check the export, and provide colour references.
These checks help the shop review the job before production. Our artwork and file guidelines page covers the general case across all categories, and the large format printing and banners and signs pages list the substrates and finishing this applies to.