Digital-to-Print Manual

High-End Inkjet Guidelines

TL;DR

Executive Summary

Color Space Always use RGB (do not convert to CMYK).

Color Profile Always embed the colour profile in the file.

File Format Use .TIF (TIFF) for the highest quality.

Resolution Set it correctly when you first create the file — resampling larger later lowers quality.

Bit Depth Use 16-bit if the image has gradients, to prevent banding.

Color Space Always use RGB (do not convert to CMYK).

Color Profile Always embed the colour profile in the file.

File Format Use .TIF (TIFF) for the highest quality.

Resolution Set it correctly when you first create the file — resampling larger later lowers quality.

Bit Depth Use 16-bit if the image has gradients, to prevent banding.

Color Space

Use RGB

Our 12-colour, wide-gamut inkjet printers mix colour differently from ordinary 4-colour offset (CMYK). Working in RGB lets the printer reach its full colour gamut — wider and more vivid.

Converting to CMYK before printing clips the gamut, and the colour comes out muted — a real shame.

Color Profile

Always Embed Profile

A colour profile is like a "dictionary," or the "brand," of the colour — it turns numbers like RGB (0, 255, 0) into a real colour (here, green).

For example:
RGB (0, 255, 0) in sRGB gives a green
RGB (0, 255, 0) in Adobe RGB gives a brighter, more vivid green
RGB (0, 255, 0) in ProPhoto RGB gives a very vivid green
(the example images are exaggerated to make the point)

Note: the same colour code in different profiles produces different colours. So make sure the colour profile is always embedded in the file. (Without it, most software assumes sRGB, which can shift the colour if the original was not made in sRGB.)

Note: a wide-gamut profile like Adobe RGB does not guarantee the print will be that vivid — it also depends on the paper and what the printer can do.

Bit Depth

Use 16-bit for Gradients

Bit depth is how finely colour can be graded.

8-bit

Grades from black to white in 256 steps.

16-bit

Grades in up to 65,536 steps.

When should you use 16-bit? If the file has gradients or wide skies, 16-bit prevents "colour banding" (uneven, stepped colour that should be smooth).

Note: the software with full 16-bit support is Adobe Photoshop. Illustrator (vector) and Procreate may have limits on some functions when exporting 16-bit files.

File Types

TIF (TIFF)

Many image formats can hold high resolution, but you need to pick the one suited to printing.

TIF (Tagged Image File Format)

The standard for high-quality printing: it saves losslessly (no quality-destroying compression) and supports LZW compression, which shrinks the file without losing quality.

PSD

A good master file, but a proprietary Adobe format. Compatibility problems can arise if the print shop lacks the fonts or runs a different version.

JPG

Not recommended for fine-art printing — it compresses lossily, so detail is lost every time you save.

Resolution

300-600 DPI

Resolution (for bitmap/raster images) must be set correctly when you first create the file. Upscaling or resampling a small image later cannot add real detail.

Standard Printing

Normally 300 DPI.

High-End Inkjet / Fine Art

For high-quality paper with very fine detail (e.g. type at 10pt or smaller), 600 DPI gives noticeably sharper results.

Large Format (A1, A0+)

For large prints meant to be viewed from a distance, you can drop to 150–240 DPI without the eye telling the difference — keeping the file from getting larger than it needs to be.

Tip: to check whether a resolution is right, consult a printing specialist, weighing the physical print size, the paper, and the viewing distance.