How to Build a Large Format File

Start With Two Numbers, Not With Photoshop

Before you open anything, write down the finished size and the viewing distance. Every other decision in this guide comes from those two numbers, and getting them first is what prevents the most expensive mistake in large format: building a beautiful file at the wrong scale and finding out at proof.

Large format does not work like print you hold in your hand. A 40-foot wall does not need the resolution of a brochure, and treating it like one produces a file so large nobody can open it, for no visible gain.

Step 1: Pick Your Scale

You have two workable approaches, and both are correct.

Build at 10 percent of final size at 300 dpi. A 20-foot banner becomes a 2-foot document. This keeps the file manageable and the math clean, and it’s the approach most designers find easiest to hold in their head.

Or build at full size somewhere between 30 and 100 dpi, choosing the number based on how close the viewer gets. This is more intuitive for layout because you’re working at true scale, but the document gets heavy fast.

Either way, put the scale in the filename. A file named at 10 percent that gets treated as full size is the single most common preventable error we see.

Step 2: Match Resolution to Viewing Distance

Resolution should follow how the finished piece is actually seen. We print at 70 and 150 dpi for grand format outdoor work read from across a street or a parking lot, and 330 and 660 dpi for close-viewing pieces like trade show graphics and retail displays.

That means your file only needs to carry enough data to feed the resolution the job calls for. Building a building wrap at 300 dpi at full size produces a file nobody can process and a print that looks identical to one built correctly.

When in doubt, ask before you build. It takes a minute and it sets the whole document up right.

Step 3: Build Vector Wherever You Can

Vector artwork from Illustrator or InDesign scales to any size with no quality loss. For logos, type, icons, rules, and hard-edged shapes, there is no reason to use anything else.

Photographic content has to be raster, so most real jobs end up a mix: vector type and logos placed over a linked high-resolution image. That’s the right structure. Keep the vector elements vector all the way through, and resist flattening the file to “simplify” it, because flattening turns sharp type into pixels permanently.

Step 4: Judge Your Images at 100 Percent

Screens display at roughly 72 to 110 pixels per inch, at a size far smaller than the finished print. That’s why a low-resolution file can look perfect on a monitor and fall apart on a wall.

A file that looks sharp at 1,200 pixels wide on your screen is being asked to cover 12 feet, which stretches every pixel to about a tenth of an inch. Fit-to-screen is lying to you.

So zoom to 100 percent at final size and look at the actual pixels. If it’s soft there, it will be soft in print, and no amount of upsampling fixes it.

Step 5: Set Up Color in CMYK

Build in CMYK for anything going to press. RGB files get converted, and that conversion can shift saturated blues, greens, and oranges noticeably. Converting on your side means you see the shift and can correct it, instead of being surprised by it on the print.

For brand colors that have to match exactly, supply the Pantone values separately rather than relying on the file alone. A PMS number from a current chart is far more reliable than a description or an on-screen sample, because monitors vary and so does the lighting the finished graphic is viewed under.

If you have a physical swatch or a previously approved printed piece, send it. Matching to a physical reference beats matching to a number.

Step 6: Ask for the Bleed Spec Before You Build It

Any piece that gets trimmed, wrapped around a frame, or stretched over a structure needs bleed. The amount depends entirely on the finishing method, and this is where designers get caught out.

SEG fabric, pole-pocket banners, and hardware-mounted rigid pieces each need a different allowance, and there is no universal number. A file built with the wrong bleed either loses content into a frame channel or leaves an unprinted edge at the install.

Ask for the bleed spec for your specific finishing before you build the file, not after. It’s a one-question email and it’s the cheapest insurance in this entire guide.

Step 7: Outline Your Type and Package the File

Outline all type before sending, or package the fonts with the file. Outlining removes any chance that a font substitution quietly changes your layout on a machine that doesn’t have your typeface installed.

Keep a live-text version on your side for future edits. Outlined type can’t be edited, and you will need to change a date eventually.

We accept most popular formats, including Photoshop, Illustrator, InDesign, EPS, TIFF, high-resolution PDF, CorelDraw, and QuarkXPress. Include linked images and any Pantone references with the package.

Step 8: Send It

Use the upload page on our site. No password, no login, and no special software is required, and it handles files far larger than any email system will accept. Files under 10 MB can also be emailed to art@xldigital.com.

If you’re unsure about any of the above, send the file anyway and say what you’re unsure about. Prepress, an electronic proof, minor revisions, and color matching are all included in the project price rather than billed separately, so raising a question early costs you nothing.

Simple text changes, like swapping a date or a directional arrow on a file you’ve already supplied, are made at no charge. And if you’re working against a fixed install date, say so at the quote stage: rush orders ship within 36 hours of file approval.