A Note about Colors

Most of the time, color in print-on-demand is pretty straightforward: design your image in RGB color space, save it in large size/high resolution with PNG format with transparent background ... and you're done.

But there are cases where colors become quite complicated, especially if you're trying to print a specific hue.

Let's delve into the nitty gritty of colors in printing, why it's difficult to match a specific color and what we can do if you need to do just that.

RGB vs CMYK

The colors you see on the computer monitor come from red, green, and blue (RGB) light emitting diodes (LEDs) that are literally shining light into your eyes.

The colors you see on the garment are reflected light from a combination of cyan, magenta, yellow, black (CMYK) and white ink on a matte cloth surface.

The RGB color space is larger than that of CMYK. Furthermore, the colors you see on your monitor are backlit, shining rays of light so they can appear very vibrant.

Please keep in mind that our perception of color is also affected by the background and surrounding colors, as well as the lighting of the room.

Limitations of Printing with CMYK ink

Color Shifts - When you're trying to print a color that is within the RGB color space but is outside the CMYK color space (technically, outside the CMYK gamut or printable colors of the printer), then you'll get a color that is not the exact shade or hue.

Certain colors are hard for CMYK printers to hit, such as florescent or neon-y pink, purple, orange, and green colors.

Muddy Dark Colors - Dark shades of grays, navy and other dark colors are difficult to print. For example, you can see fine gradients of gray colors on your monitor that a printer just can't replicate. When printed on cloth, dark colors will look muted and muddy (unlike dark colors on LED monitors which can appear vibrant because of the backlit pixels).

Metallic Colors and Glow-in-the-Dark - There are no metallic and glow-in-the-dark inks for CMYK printers, so these are just not doable. That said, there are specialty transfer films that claim to have metallic and glow-in-the-dark effects, but in our experience, the effect is quite weak.

If you must have metallic or glow-in-the-dark effect, the best way to do it is with screen printing or heat transfer vinyl (HTV).

PMS Colors - In screen printing, the print shop can hit a specific, exact color by using PMS (Pantone Matching System). If you need a specific shade of green, the print shop will use the specific PMS numbered ink that is for that exact color. There is no way to replicate that with CMYK ink set.

Matching Colors using a Digital Swatch - It's tempting to think that you can use a digital color picker to "match" a specific color (either for the image to print, or to match the color of the garment) on your screen, but this is not reliable.

In addition to the RGB vs CMYK limitation (see above), there are additional reasons why this isn't a good way to match colors. For example, different monitors show different colors because they aren't calibrated the same. The color you see on your monitor can be very different from what others see on their monitors.

If you're trying to match a garment color, please keep in mind that the digital swatches we get from the mill are often different from the actual shirt colors because of dye lot variability.

What to do if you really want to print a specific color

With all the caveats above, it is possible to print a specific color (or get as close as possible to it): you can request physical printed swatches for Flex Digital Print. This way, you can see and match the color you want, and use the corresponding RGB value in your image.