Color management in sublimation printing

The colors seen on a computer screen never exactly match those of printed jobs. This is because the colors of the screens are generated by the combination of three colors: red, green and blue (RGB).

In contrast, digital printers use between four and eight colors of ink to reproduce the image on the screen. CMYK (cyan, magenta, yellow and black) is the standard for digital printing in four colors.

Computer monitors emit color in the form of RGB light. Although all colors of the visible spectrum can be produced by combining red, green and blue light, monitors are only able to reproduce a limited range of colors of the visible spectrum.

The printed products absorb or reflect specific lengths of light, unlike a screen that emits light. The pigments or dyes of cyan, magenta and yellow color work as filters, subtracting from the white light different shades of red, green and blue to produce a selective range of spectral colors.

As you can see, there is a clear difference in the functioning of both ways of generating color. One is additive; the other is subtractive. In the decoration of digital products, the design is made in an additive environment (RGB); later, the printer and the software convert these colors so that they can be used in a subtractive environment (CMYK). The management (or color correction) is the process of adjusting this chromatic transformation so that it produces the highest quality results on the chosen substrate.

Specific challenges posed by sublimation
With the sublimation of inks another element of the color control process comes into play. When the sublimation transfer paper of inks is ironed onto the substrate, the ink is transformed into a gas that adheres to the polymers of the substrate. During this “gasification” process, some colors change; therefore, the finished product does not have the same appearance as the original image on the screen.

You may also notice that the colors of the ink printed on the transfer paper are quite different from the final image created by applying heat and pressure. This is due to the chemical characteristics of the dye sublimation process, and it is another factor that requires applying a color correction process.

With sublimation, these issues must be addressed in each combination of specific inks and printers. In extreme circumstances, it may be necessary to correct the color for all combinations of substrates and printer inks and transfer paper.

Anyway, a series of exhaustive tests have shown that, in most cases, a transfer paper of good quality does not affect the final color. Therefore, we recommend using only high quality paper.