My CMYK JPEG looks strange in the browser — why?

Many browsers and viewers display CMYK JPEGs inaccurately. The Image Resolution Checker will tell you whether a file is CMYK.

Should I convert to CMYK to preview dull colours?

Use your printer’s profile with Photoshop’s soft proof (View → Proof Setup) rather than converting the file itself.

RGB vs CMYK for Textile Printing

Designers coming from paper print are often told “always send CMYK”. Textile printing is different, and sending the wrong colour mode is a common cause of dull or shifted colours.

Two colour models

RGB describes colour as light — red, green and blue added together on a screen. CMYK describes colour as ink — cyan, magenta, yellow and black subtracted from white paper. Each model can describe a different range of colours, called its gamut.

How digital textile printers work

Most digital textile printers use reactive, acid, disperse or pigment inks, frequently with extra colours beyond CMYK such as orange, red, blue or grey. Their software (the RIP) converts your file to the printer’s own ink set using colour profiles built for a particular fabric and dye.

Because the printer converts colours itself, many textile printers prefer RGB files with an embedded colour profile (commonly sRGB or Adobe RGB). Converting to a generic paper CMYK profile first can throw away colours the textile printer could have reproduced — especially bright oranges, pinks and turquoises.

Some bureaus, particularly those running CMYK-only pigment systems or screen print separations, do ask for CMYK. The rule is simple: follow your printer’s instructions, and if they say nothing, ask.

Why colours still shift

Screens emit light; fabric reflects it. Saturated screen colours, especially neons, may be out of gamut for any dye.
Fibre and dye matter. The same file printed on polyester (disperse dye), cotton (reactive) and silk (acid) can look noticeably different.
Base colour. Natural, ecru or slub fabrics tint every colour printed on them.
Uncalibrated monitors make every decision less reliable.

A practical workflow for predictable colour

Work in RGB with a known profile and calibrate your monitor if you can.
Build palettes deliberately — the Textile Color Palette Tool helps you plan a ground colour and accents.
Order a colour chart or colour map from your printer on the exact fabric you will use, and pick colours from it.
Use the printed chart’s RGB or hex values in your artwork.
Approve a strike-off before production.

What about Pantone and spot colours?

Pantone’s textile systems describe colours as dyed fabric swatches. They are useful for communicating a target colour to a mill, but digital printers can only approximate them. For screen printing and yarn-dyed work, spot colours and lab dips are standard.