Print color checker: a free CMYK color test before you print
Which colors in an image ink cannot reach, and a preview of how they will print instead.
or drop one here. It stays on your device: nothing is uploaded.
How to read the result
- On screen / In print. Switch between the two. Where nothing moves, the color prints as it looks. Where the picture goes flatter, that is the printer's closest match.
- Show only what changes. Everything that prints as it looks is dimmed, so the colors at risk stand out.
- The colors that lose the most. Each pair is a color from your picture and the closest one ink reaches, with how much of the picture it covers.
Print color vs screen color: RGB and CMYK
A screen is a lamp. Every pixel shines red, green and blue light straight at you, and at full strength those lights are purer than any pigment. A print is the opposite: white paper or fabric with ink on it, and the ink can only take light away. Cyan, magenta, yellow and black, laid over each other, cover a smaller set of colors than a screen does.
What falls outside is the bright, pure end of the range: neon green, electric blue, hot pink, glowing violet. A printer does not leave those out. It prints the closest color it has, and the picture comes back a little flatter and darker than you remember it.
Clothing loses more than paper. Cotton drinks the ink in and spreads it a little, so colors come out softer and darker than on a coated poster. On a dark shirt the printer first lays a layer of white ink under the design, and the colors on top of it rarely reach the brightness of a screen. A neon green that glows on a phone often prints as a plain grass green.
What to do about the colors it marks
- 1Decide whether it mattersA few percent in small highlights will not be missed. A logo, a background or the main subject in a marked color will.
- 2Make it again with colors that printAsk for a look that comes from print: “screen print”, “risograph”, “gouache”, “vintage poster”, “limited palette”. Leave out “neon” and “glowing”.
- 3Or tone it down yourselfLower the saturation of the marked colors until the two views nearly match. The picture is less vivid either way; this way you choose how it looks.
- 4Do not convert it to CMYKPrint-on-demand suppliers ask for sRGB files and convert them on their own printers. Keep the file in sRGB.
The longer version, with example prompts, is in why AI art prints duller than it looks on screen.
How to test print color before ordering merch
- 1Check the file here firstIt costs nothing and takes a few seconds. If the main colors of the design are marked, fix them before anything is printed.
- 2
- 3Order one before you order manyA single test print on the real product is the only exact color test. Hold it next to your screen in daylight, not under a lamp.
What this cannot tell you
No screen can show a print exactly, and no two printers are the same. The preview uses the standard reference for four-color ink on coated paper (the FOGRA39 measurements). A poster printed with extra inks reaches a little further; a cotton shirt reaches less. Take what is marked here as the least that will change, and order one before you order many.
Color is one of three checks worth a minute before printing. The print size calculator covers resolution and the transparent PNG checker covers backgrounds.
Read more on the blog
- Why AI Art Prints Look Dull or Dark (RGB vs CMYK Fix + Free Checker)
- RGB vs CMYK for Print on Demand: How to Keep Bright Colors on Custom Merch
Questions people ask
Why do my prints look duller than my screen?
A screen makes color by shining light, and ink can only take light away from white paper or fabric. The brightest, purest screen colors (neon green, electric blue, hot pink, glowing violet) have no ink that matches them, so a printer uses the closest color it has, which is flatter and usually a little darker.
Which colors cannot be printed?
The very saturated ones: pure RGB green and blue, bright cyan, magenta and violet, and anything described as neon or glowing. Reds, oranges and yellows lose less. Earth tones, pastels, skin tones and greys print as they look.
Should I convert my file to CMYK before uploading it?
For print on demand, no. Suppliers such as Printful ask for RGB files in the sRGB color profile and convert them on their own printers. Converting first throws color away twice. Keep the file in sRGB and choose colors that survive the trip.
How accurate is the print preview?
It is a guide, not a proof. It shows the closest colors that standard four-color inks reach on coated paper, worked out from the FOGRA39 print measurements. Each printer, ink and material differs, and fabric usually reaches fewer colors than paper, so treat what it marks as the least that will change. A sample order is the only exact answer.
Is my image uploaded anywhere?
No. The file is opened and checked in your browser, on your own device. Nothing is sent to SlapMake or to anyone else.
More tools
How large an image prints, the DPI at any size, and how many pixels a photo, poster, shirt or A4 page needs.
OpenEvery Etsy fee on a sale, what is left after production and shipping, and your break-even price.
OpenIs the background really transparent? Find faint leftovers and stray specks, and clean them.
OpenCut a design out of its background and download a transparent PNG at full size. No sign-up.
OpenMake an image 2× or 4× bigger with AI, so it prints sharp. Keeps a transparent background.
OpenMake pictures larger or smaller: to exact pixels, a percentage, or a print size at 300 DPI.
OpenMake picture files smaller: at a quality you choose, or under a size such as 100 KB.
OpenTrace a logo, drawing or AI image into an SVG of clean shapes, and get a sharp PNG at print size.
OpenThe shape of any picture, the same shape at another size, and the frames and posters it fills without cropping.
OpenType what should be on the shirt, tap a style, a mood and colors, and copy a prompt made for printing.
Open