Lesson 9: Preparing Images for Print

Start with the screen

Most screens are set far brighter than paper can look under ordinary room light, which is the most common reason prints come back looking too dark. A hardware calibrator measures your display and builds a profile so it shows color accurately, and lowering the screen's brightness for print work — a commonly recommended range is roughly 80–120 cd/m² — brings what you see closer to what paper can show. Remember too that a print reflects light rather than emitting it, so it can't span as wide a range from deepest black to brightest white as a screen; paper has less dynamic range to work with, and some contrast has to be managed rather than kept.

Color spaces, in practice

Color profiles (sRGB, Adobe RGB, ProPhoto RGB) define the range of colors a file can represent. sRGB suits web display; wider spaces suit print, but only if your entire workflow — camera, software, printer — stays consistent. Mismatched profiles at any stage are a common cause of prints looking different from the screen.

sRGB is the smallest of the three and the standard for screens and the web. Adobe RGB covers more greens and cyans, some of which good photo printers can reproduce. ProPhoto RGB is larger still and mainly used as an editing space for RAW files; it should be used with 16-bit files, because in 8-bit its wide range is spread across too few steps and smooth gradients can band. If you shoot RAW, the camera's color space setting only affects the JPEG preview — the space is chosen when you export. Two habits prevent most problems: always embed the color profile when exporting, and send a lab the color space it asks for. Many consumer labs expect sRGB and convert anything else, not always well.

Pixels, PPI and print size

Resolution and print size depend on pixels-per-inch at final size, not total megapixels. 300 PPI is a solid standard for close-viewing prints; larger prints viewed from further away can use lower PPI without perceptible loss.

PPI describes how densely the file's pixels are spread on paper; DPI describes the printer's ink dots — a different thing, although the two terms are often mixed up. To find the largest print at a given PPI, divide the pixel dimensions by it: a 6000 × 4000 pixel file at 300 PPI prints at 20 × 13.3 inches (about 51 × 34 cm), and at 240 PPI the same file prints at 25 × 16.7 inches. The Print Size Calculator works it out in either direction. If a file is short of pixels for the size you need, enlarge it yourself at the end of the edit, in your editing software or a dedicated upscaler, and check the result at 100% rather than leaving the lab to stretch it.

Preparing a print file, step by step

1. Finish the edit on a calibrated screen at a print-friendly brightness.
2. Soft-proof with the profile for the exact printer and paper — labs often publish theirs — and turn on the gamut warning to see which colors the paper can't reproduce.
3. Make print-specific adjustments on a copy, typically small brightness and saturation changes where the soft proof shows dull shadows or out-of-gamut colors.
4. Crop to the print's aspect ratio. A 3:2 camera file fits 4 × 6 and 8 × 12 inch prints without cropping; 8 × 10 inches and the A paper sizes need a crop.
5. Resize to the final print dimensions at the resolution the lab recommends, then apply output sharpening for the paper type. Matte papers generally need more than glossy, because ink spreads more on a matte surface.
6. Export with the requested color profile embedded, as a high-quality JPEG or a TIFF, whichever the lab accepts.
7. Order a small test print before committing to a large or expensive one.

Soft-proofing simulates how an image will look on a specific paper/printer combination before you print — catching color or contrast issues while they're still easy to fix.

Paper choice affects the image itself: glossy paper reproduces higher contrast and saturation; matte renders softer, lower-contrast tones. Worth factoring into your editing decisions when you know a specific image is destined for print.

A worked example

A landscape from a 24-megapixel camera (6000 × 4000 pixels) is going to be printed at 16 × 24 inches on matte paper. At that size the file gives 250 PPI — plenty for a print of that size seen from a normal viewing distance — so no enlargement is needed, and the 2:3 print shape matches the file, so no crop either. Soft-proofing with the lab's matte profile shows two problems: the deep blue sky is partly out of gamut, and the darkest rock shadows merge into one tone. On a print copy, saturation in the blues comes down slightly until the gamut warning mostly clears, and the deepest shadows are lifted a little to keep their separation. After matte-paper sharpening, the file is exported as a TIFF in Adobe RGB, which this particular lab accepts. A small test print of one section confirms the shadow detail holds before the full-size order goes in.

Common mistakes

• Editing on an uncalibrated screen at full brightness, then blaming the lab for dark prints.
• Sending an Adobe RGB or ProPhoto file to a lab that expects sRGB.
• Confusing PPI with megapixels, or with the printer's DPI.
• Ignoring highlight clipping. Pure white areas print as bare paper with no texture at all, which can look like a hole in the image — especially on off-white or warm-toned paper.
• Printing the file sharpened for the screen. Output sharpening depends on print size and paper.
• Skipping the test print on a large or expensive order.