Poster print file checklist: size, bleed, resolution and fonts

What file format is best for poster printing?

PDF is the standard handoff for print because it carries the page size, vector shapes, embedded fonts and placed images in one file. Print shops that work to the PDF/X family of standards, published as ISO 15930, expect fonts to be embedded, the trim size to be defined by a TrimBox and any bleed to sit outside it in a BleedBox. A JPG or PNG can work for a poster that is a single photograph, but it flattens text into pixels and cannot carry vector type. If you are weighing the two, the comparison of PDF or JPG for posters explains when each makes sense.

Keep the editable source file as well. The PDF is what prints; the source file is what you edit when the date changes next season.

What size should the poster file be?

Build the document at the finished size and add bleed on every side. With the common 0.125 inch allowance, the file grows by a quarter inch in each direction. The table lists four common poster sizes with that bleed and a 0.25 inch safe margin inside the trim.

Confirm orientation before you start. A portrait 18 x 24 and a landscape 24 x 18 are different files, and rotating a finished layout rarely works without rework. The guide to poster bleed and trim covers the geometry in more depth, including frame allowances.

What resolution do poster images need?

Resolution is measured at the placed size, not the original size. Divide the image's pixel width by its printed width in inches to get effective pixels per inch. The U.S. Government Publishing Office asks for photographs scanned at 300 pixels per inch at a one to one input to output ratio, and Voqado's poster guidance asks for at least 150 at final print size, with 300 recommended for the sharpest results. Posters viewed from across a room tolerate the lower end; posters read up close, such as event schedules at eye level, benefit from the higher end. The poster resolution guide includes a full pixel table by size.

Crop and scale images in an image editor before placing them, as GPO recommends, so the layout file does not hide how few pixels remain after a heavy crop.

How should fonts be handled in a poster file?

Embed every font in the exported PDF. If a font cannot be embedded because of its license, convert the text to outlines in a copy of the file, keeping the live text version for future edits. Check for substituted fonts, missing glyphs and very thin strokes, which can break up at large sizes. Size matters as much as embedding: headline and body sizes should be chosen for the distance the poster will be read from, which the poster font size guide works through by viewing distance.

Should a poster file be RGB or CMYK?

Ask the printer. Process color presses print in CMYK, and GPO's guidelines ask for CMYK files for four color work, warning that converting from RGB causes a color shift. Some digital production workflows accept RGB and handle conversion themselves. The current Studio export produces RGB PDFs with embedded fonts and trim and bleed boxes; it does not perform calibrated CMYK conversion or produce certified PDF/X files. If exact color matters, such as a brand color or a product photograph, request a physical proof and read the color proofing guide before approving.

How do you check the exported poster PDF?

Open the PDF itself, not the design file, and confirm the page size equals the finished size plus bleed. Use the preflight or output preview panel in your PDF software to check that fonts are embedded and that the TrimBox and BleedBox are where you expect. Zoom to 100 percent and scroll every edge for white gaps. Inspect each photo at 100 percent for pixelation. Turn off any guide or template layer before exporting, and check that transparent effects, such as drop shadows, flattened correctly.

What content checks should come last?

Visual checks and content checks are separate jobs. Read the poster aloud: event name, date, day of the week, time, venue, prices, phone number and web address. Check that the day matches the date. Scan any QR code from a printed test at actual size and open the destination. Ask someone who did not design the poster to read it, because the designer's eye fills in what it expects to see. A file named final can still contain last year's date, so approve the exact file you reviewed, not a filename.

What should a poster preflight checklist include?

• Document at the finished size, in the correct orientation.
• 0.125 inch bleed on every side, or the printer's stated allowance.
• Backgrounds and edge to edge photos extended through the bleed.
• All text and logos inside a safe margin of at least 0.25 inch.
• Every photo at 150 to 300 effective pixels per inch at placed size.
• All fonts embedded, or outlined in a copy when embedding is not allowed.
• Color mode confirmed with the printer; physical proof requested if color is critical.
• Exported PDF checked for page size, TrimBox, BleedBox and edge gaps.
• Dates, prices, contact details and codes proofread by a second person.

When all nine items pass, upload the PDF for custom posters and review the proof at the size you ordered.