Preparing Print-Ready Artwork

Illustration · ~8 min read

You can paint something beautiful and still have it rejected by a printer, or worse — printed badly — because of a handful of technical settings. Print-ready artwork means the file arrives at the right size, resolution, colour space and colour separation. This guide walks through the settings that matter, in the order you should check them.

Resolution: 300 dpi at final size

Print resolution is measured in dots per inch (dpi) for output, and pixels per inch (ppi) for the image file. The industry default for illustrated books is 300 ppi at the final printed size. The key phrase is "at final size": a 300 ppi image that you then enlarge to fit the page drops below 300 and will print soft.

To find the pixels you need, multiply the printed dimension in inches by 300:

• A 250 mm wide page is about 9.85 inches, so you need roughly 2,955 pixels across.
• A double-page spread with bleed needs even more, because you must include the bleed area.

Some fine-art and large-format work accepts 200–250 ppi, and a deliberately grainy or textured style can tolerate 240 ppi. Below 200 ppi, softness becomes visible. Above 300 ppi you are mostly wasting file size — though oversampling line work can help clean anti-aliased edges before downsampling.

Bleed: 3 mm extra on every edge

If an image runs to the edge of the page, it must extend past the trim so that tiny cutting variations do not leave a white sliver. 3 mm bleed on all four sides is the common standard, though some printers ask for 5 mm. So a 250 × 250 mm page with bleed becomes a 256 × 256 mm canvas.

Equally important are the safe margins. Keep important content — faces, text, fine detail — at least 5 to 10 mm inside the trim. On a double-page spread, remember the gutter, the centre where the book is bound: do not place a crucial element there, because it disappears into the fold. If you can, allow about 10–15 mm on each side of the gutter as a caution zone.

Colour: RGB on screen, CMYK in the press

You paint in RGB — additive light — but commercial presses print in CMYK, a subtractive ink model. Bright RGB colours, especially vivid greens, oranges and neon hues, cannot be reproduced exactly in ink; they shift, usually becoming duller. The professional workflow is to convert to CMYK at an agreed point and then check the result, rather than letting the printer convert it blind.

Practical steps:

1. Ask the printer or art director for the target profile. Common commercial print profiles aim at coated or uncoated stock.
2. Convert a duplicate of your file to CMYK using that profile; never destroy your RGB master.
3. Compare the conversion side by side. Soft-proofing (simulating ink on screen) helps.
4. Adjust any colours that broke badly, usually the most saturated ones.

File formats

Printers usually want one of a small set of formats:

• PDF — the standard for page-layout and press-ready files; supports embedded fonts and CMYK.
• TIFF — lossless raster, good for single illustrations, large but reliable.
• PSD-style layered raster — often accepted as source art, not usually as final press file.
• EPS or PDF vector — for logos, line art and anything that must scale.
• PNG and JPEG — screen formats; avoid for print finals, especially JPEG, which loses data.

Keep your layered master. Flatten and export a copy for the printer. If they later request a change, you want the layered original available.

Fonts, text and outlines

If you have placed any text — a title, a signpost in a scene — embed the fonts when exporting a PDF, or convert them to outlines. Missing fonts get substituted by the printer and your carefully set lettering shifts. If the book's typography is handled by a designer, leave a generous empty area for their text and never bake the main story text into the artwork yourself.

A pre-flight checklist

Before you hand anything over, run through this list. It takes ten minutes and prevents most rework rounds:

1. Canvas is trim size plus bleed, at 300 ppi.
2. Nothing important sits inside the safe margin or over the gutter.
3. File is converted to CMYK using the agreed profile.
4. Text is 100% black; large blacks are rich black.
5. Fonts embedded or outlined.
6. Images are flattened appropriately and free of stray alpha channels.
7. File is named to the client's convention, with a version number.
8. A low-resolution PDF proof is included for quick checking.

Proofs and test prints

A digital proof on screen is a guide, not gospel; screens vary hugely. Ask for a hard proof — a physical print — for anything colour-critical. For a picture book, a printer's proof or a single printed signature lets you judge how your palette actually behaves on the chosen paper. Paper matters too: the same ink looks different on coated gloss versus matte uncoated stock, and heavier paper often suits illustration better.

Common mistakes

• Enlarging a 300 ppi image after the fact, dropping its effective resolution.
• Forgetting bleed and leaving white slivers after trimming.
• Sending RGB files and hoping the printer's conversion is kind.
• Placing a key element dead centre on a spread, where the binding swallows it.
• Trusting a screen soft-proof to judge final colour.

Print preparation is unglamorous, but it is the difference between a book that looks like the one you painted and one that looks like a cheaper cousin of it. Build the checklist into your export routine and it becomes automatic.