Print Export

• 01
  Calculate the Required Pixel Dimensions for Print

  The formula is straightforward: pixel dimension = print size (inches) × required PPI. A 10 × 8 inch print at 300 PPI requires 3000 × 2400 pixels. A 20 × 30 inch large-format poster at 150 PPI requires 3000 × 4500 pixels. Check your image's current pixel dimensions against the requirement: Image → Image Properties shows width, height, and current PPI. If the image is too small, do not simply upscale — upscaling adds pixels by interpolation, not real detail, and the result prints softer than the pixel count suggests. The practical rule: an image can be upscaled by up to 110–120% of its native size without visible degradation using cubic or sinc interpolation. Beyond that, the source photograph does not contain enough information for the print size and must be reshot or accepted at a lower PPI.

  Formula: print width (in) × PPI = required pixel width · Image → Image Properties to check current dimensions
• 02
  Set Image Resolution (PPI) Without Resampling

  If your image has the correct pixel count but the wrong PPI metadata, correct the metadata without resampling. Go to Image → Scale Image. In the dialog, uncheck the chain link between Width/Height and Resolution, then change the X Resolution and Y Resolution values to 300 (or whichever PPI your print vendor requires) and click Scale — if no pixel count fields changed, the pixel dimensions are unchanged and only the metadata was updated. Alternatively, use Image → Print Size, which changes the PPI metadata directly without touching pixels. The distinction matters: resizing by changing pixel count resamples the image (interpolates new pixels); changing only the resolution metadata does not touch a single pixel.

  Image → Print Size → set X/Y resolution to 300 PPI (changes metadata only, no resampling)
• 03
  Assign and Convert ICC Colour Profiles

  GIMP manages colour through ICC profiles. Two operations exist and must not be confused. Assign Profile (Image → Color Management → Assign Color Profile) tells GIMP how to interpret the existing pixel values — use this when a file has no embedded profile or an incorrect one. Convert to Profile (Image → Color Management → Convert to Color Profile) actually remaps the pixel values from one colour space to another, changing them to match the visual appearance as closely as possible in the new space — use this when your source is in one RGB space (e.g. Adobe RGB) and you need to deliver in sRGB. For print handoff, ensure the image is tagged with the correct output profile — typically sRGB IEC61966-2.1 for general offset print (the print vendor's RIP handles the CMYK conversion using their press profile), or a specific CMYK simulation profile if your vendor requests one.

  Image → Color Management → Assign Color Profile (tag only) · Convert to Color Profile (remap pixels)
• 04
  Download and Install a CMYK ICC Profile for Soft Proofing

  Soft proofing requires a CMYK ICC profile that describes the ink-on-paper behaviour of the target printing process. The most widely used profiles are published free by standards bodies. Fogra39 (ISO Coated v2) is the European standard for coated offset print — the most common for commercial work. SWOP v2 is the North American equivalent. GRACoL 2006 Coated1v2 is the current North American standard for high-quality sheetfed offset. Download these from the International Color Consortium at icc.color.org or from the ECI (European Color Initiative) at eci.org. Install by placing the .icc or .icm file in your system's ICC profiles folder: ~/.local/share/color/icc/ on Linux, ~/Library/ColorSync/Profiles/ on macOS, or C:\Windows\System32\spool\drivers\color\ on Windows. Restart GIMP after installing.

  Download Fogra39 from eci.org → install to system ICC folder → restart GIMP
• 05
  Enable Soft Proofing to Preview CMYK Conversion

  With a CMYK profile installed, enable soft proofing: View → Color Management → Softproof Colors (or press Shift+Ctrl+P in GIMP 3.x — check your actual key binding under Edit → Keyboard Shortcuts). In View → Color Management → Proof Setup, select your CMYK profile (e.g. Fogra39) and set the Rendering Intent. Relative Colorimetric with Black Point Compensation enabled is the correct choice for most photographic print work — it maps out-of-gamut colours to the nearest reproducible value while preserving in-gamut colours exactly. Perceptual compresses the entire colour gamut proportionally — use it only when the image contains many highly saturated colours that all need to shift together rather than clip. Enable Gamut Warning (View → Color Management → Mark Out of Gamut) to overlay a warning colour (usually grey) on any areas that cannot be reproduced in the target CMYK space.

  View → Color Management → Proof Setup → select CMYK profile → Relative Colorimetric + Black Point Compensation
• 06
  Correct Out-of-Gamut Colours Before Export

  With soft proofing and gamut warning active, any area displayed with the warning overlay colour cannot be printed in the target CMYK space. The most common culprits are saturated blues (CMYK struggles with vibrant blue), vivid cyan-greens, and bright oranges. To bring these into gamut, use Colours → Hue-Saturation with soft proofing still active: select the relevant colour range (e.g. Blues) and reduce Saturation until the gamut warning disappears from those areas. Make the minimum adjustment needed — desaturating more than necessary will make the final print look flat. Work on a duplicate layer so you can compare before and after by toggling the duplicate's visibility.

  Colours → Hue-Saturation → select colour range → reduce Saturation until gamut warning clears
• 07
  Sharpen Specifically for Print Output

  Print sharpening is different from screen sharpening. The dot gain of offset printing — ink spreading slightly as it absorbs into paper — softens fine detail. Images must be sharpened more aggressively for print than for screen. At 300 PPI offset print, apply Unsharp Mask with Amount 0.65–0.85, Radius 1.2–2.0 px, Threshold 3. At 150 PPI large-format inkjet, use Amount 0.5–0.7, Radius 2.0–3.5 px, Threshold 4. Always evaluate print sharpening at the intended print size, not on screen at 100% zoom — print sharpening that looks heavy on screen is often correct at output. The standard test: zoom the image in GIMP to the actual print size (View → Zoom → set to a percentage that approximates how the image will look at arm's length from the printed page) and assess there.

  Filters → Enhance → Unsharp Mask → Amount 0.7, Radius 1.5, Threshold 3 for 300 PPI offset print
• 08
  Export as TIFF with the Correct Settings

  Flatten the image first: Image → Flatten Image. Then File → Export As, name the file with a .tif extension. In the TIFF export dialog: set Compression to None for maximum compatibility (some prepress workflows cannot handle LZW or ZIP TIFF) — if your vendor explicitly requests LZW, use it. Set Bit Depth to match your working precision: 8-bit per channel for standard output (yields 24-bit RGB TIFF), 16-bit per channel if your source was 16-bit and your vendor can accept 16-bit TIFF. Ensure Save colour profile is checked — embedding the ICC profile is mandatory for correct colour reproduction at the RIP. Leave Save layers unchecked — most RIPs reject multi-layer TIFFs. Do not save alpha channels in print TIFFs unless your vendor specifically requires a clipping channel.

  Image → Flatten Image → File → Export As → .tif → Compression: None, Save colour profile: checked
• 09
  Verify the Final File Before Sending

  After exporting, close the TIFF and reopen it fresh (File → Open). In GIMP, check: Image → Image Properties — confirm the PPI is 300 (or the required value), the dimensions in inches match the intended print size, and the embedded colour profile is listed correctly. Check Image → Mode — the file should be RGB, not Indexed or Grayscale unless specifically required. Check the Layers panel — should show a single flattened layer. If anything is wrong, correct it in the source XCF and re-export; never patch a TIFF directly. Send the vendor both the TIFF and a PDF proof if available — a PDF proof gives the vendor a visual reference for how the image should look and is the first line of defence against press surprises.

  Reopen exported TIFF → Image → Image Properties → verify PPI, dimensions, colour profile, mode
• 10
  When to Use PDF Instead of TIFF

  Some print vendors — particularly those handling brochures, books, and multi-page documents — prefer PDF/X over TIFF. PDF/X is an ISO standard subset of PDF designed specifically for prepress exchange. GIMP can export single-page PDF via File → Export As → PDF, but it cannot embed colour profiles in PDF output as of GIMP 3.2 and does not support PDF/X directly. For single-image print jobs (photographs, posters, large-format prints), TIFF remains the correct choice. For multi-page documents, text-heavy layouts, or any job going to a commercial printer that requires PDF/X-1a or PDF/X-4, compose the final document in Scribus (which has full PDF/X support and can import GIMP's TIFF exports) and export from there. GIMP is an image editor, not a page-layout application — working to its strengths means knowing when to hand off to a tool that completes the job.

  Single image → TIFF handoff · Multi-page / PDF/X required → export TIFF from GIMP, compose in Scribus

Choose any photograph. You'll prepare it for printing at A4 size (210 × 297 mm / 8.27 × 11.69 inches) at 300 PPI on a standard coated offset press. The target profile is Fogra39. Install the profile before starting if you haven't already.

• A
  Check and set pixel dimensions

  A4 at 300 PPI requires 2480 × 3508 pixels (portrait). Open Image → Image Properties and check the current pixel dimensions. If the image is larger, scale it down to 2480 px on the short dimension using Image → Scale Image with Interpolation set to Linear. If it is smaller, note how far short it falls — if within 120% of the required size, scale up with Sinc (Lanczos3) interpolation, which produces the best quality upscaling. If the image is significantly undersized, it is not suitable for A4 at 300 PPI without visible quality loss.

• B
  Set PPI metadata and verify print dimensions

  Go to Image → Print Size. Set X Resolution and Y Resolution to 300 pixels/in. The Width and Height fields should update to show approximately 210 mm × 297 mm (or 8.27 in × 11.69 in). If they don't match A4 exactly, your pixel dimensions differ slightly — this is fine as long as the image covers the print area. Click OK. The pixel data is unchanged; only the PPI metadata has been written.

• C
  Soft proof with Fogra39 and correct any gamut issues

  Go to View → Color Management → Proof Setup. Select the Fogra39 profile. Set Rendering Intent to Relative Colorimetric, enable Black Point Compensation. Enable soft proofing with Shift+Ctrl+P (or the equivalent binding). Enable gamut warning via View → Color Management → Mark Out of Gamut. Inspect the image. If any areas show the gamut warning overlay, open Colours → Hue-Saturation, select the affected colour range, and reduce Saturation by 5–15 points until the warning clears. Repeat for each out-of-gamut colour range. Disable soft proofing when corrections are complete.

• D
  Sharpen, flatten, and export as TIFF

  Apply print sharpening: Filters → Enhance → Unsharp Mask with Amount 0.70, Radius 1.5 px, Threshold 3. Flatten the image: Image → Flatten Image. Export: File → Export As, name it filename-print-300ppi.tif. In the TIFF dialog: Compression None, Save colour profile checked, Save layers unchecked. After export, reopen the TIFF and verify via Image → Image Properties that the PPI reads 300 and the colour profile is embedded correctly.

Some print vendors — particularly those running older prepress workflows or newspaper printing — require a CMYK TIFF rather than an RGB TIFF with an embedded profile. GIMP cannot produce a true CMYK file, but the command-line tool tifficc from the LittleCMS package can convert your RGB TIFF to CMYK using ICC profiles with full accuracy. Attempt the following without step-by-step guidance.

• →
  Install LittleCMS and run tifficc

  On Linux: sudo apt install liblcms2-utils. On macOS with Homebrew: brew install little-cms2. On Windows: download from littlecms.com. Once installed, the conversion command is: tifficc -i /path/to/sRGB.icc -o /path/to/Fogra39.icc -t 1 input.tif output-cmyk.tif where -t 1 specifies Relative Colorimetric rendering intent. The input ICC path should point to the sRGB profile embedded in your GIMP export (or the system sRGB profile). The output path points to the Fogra39 profile you downloaded. Verify the output by reopening it — GIMP will display it as a CMYK TIFF and Image → Mode should show it is not an RGB document.

• →
  Compare the RGB soft proof against the CMYK output visually

  Open the original RGB TIFF and the converted CMYK TIFF side by side in GIMP (Windows → New Window to create a second view). Compare saturated areas — blues, cyans, oranges — between the two files. The CMYK output should look very similar to the soft-proofed RGB preview from step C of the guided practice. If the CMYK output looks more saturated than the soft proof, the rendering intent or source profile did not match. If it looks more desaturated, the Fogra39 gamut is narrower than your source image content and the conversion has clipped further than the soft proof suggested — in that case, consider using Perceptual rendering intent instead of Relative Colorimetric for this specific image.