One of the things that seem to elude many starting out in sublimation is reproducing colors in a predictable and reliable manner. Without the basic tools and knowledge, color issues can be some of the most daunting challenges to overcome. Why is color management so difficult? Scanners, digital cameras, monitors and printers all reproduce color differently. The result involves several factors, piecing together a very complex puzzle.
The most basic tool for accurate color reproduction is a simple color chart. Color charts should be printed and pressed on each of the substrates being used. (All graphics courtesy the author)
While it is certainly desirable to have the color displayed on a computer monitor correspond to what comes out on a sublimated product, it is rarely the case. One aspect that makes sublimation so different is that it creates a change in the molecular properties of the dye particles under the heat and pressure in the heat press. This fact alone makes matching up an image to a monitor nearly impossible… begging the question: how do you get the accuracy of color? The answer is to follow some basic rules and use the tools the industry provides.
RGB versus CMYK
One of the biggest mistakes any sublimation decorator can make is to use the wrong color model when choosing colors. CYMK (cyan, yellow, magenta, and black) comprise the basic four colors all inkjet printers utilize. It is easy to make the assumption that, because the printer is using CMYK colors, a design should be created using the CMYK color palette. If CMYK colors are used, it’s not likely the color you are looking for to come out the same on the finished item. This is because CMYK is a set of very specific color instructions meant primarily for the offset printing world. When we are sending art to a desktop printer, the print driver is responsible for translating the information it receives into CMYK. So what color model should colors be chosen from then?
RGB (red, green, and blue) are the colors that create the images we see on every computer monitor, digital projector and television available. There are 16,581,375 colors that can be created using the RGB color model. RGB is commonly used because it is how the human eye sees color. There two basic kinds of receptors in the eye, rods and cones. The rods are what see black and white, while the cones communicate color. The cones are staggered in the eye with specific cones detecting red, green and blue. As this is the case, the RGB color model is used in many industries and all artwork for sublimation should be designed this way.
RIP software users will perform periodic linear density configurations to compensate for performance differences encountered using a printer spanning a long period of time.
The most basic tool for accurate color reproduction is a simple color chart. Color charts should be printed and pressed on each of the substrates being used. Getting a real-world representation of colors on the exact substrate that will be sublimated will achieve accuracy. Simply choose the color from the printed chart then enter the corresponding RGB number back into the graphics program. Regardless of what color you are viewing on the screen, you can have confidence that you will achieve the desired color output for each sample substrate.
One of the methods used for color correction is with ICC profiles. The International Color Consortium is a group that sets standard guidelines for color management in the digital imaging/printing world. All monitors, scanners, digital cameras and printers use ICC profiles that are found on the disc and installed with the device drivers. Color profiles simply communicate how another device has created its colors to the hardware or software and, in turn, how they should be interpreted or reproduced.
In sublimation, ICC profiles are created to match the specific ink being used with a specific substrate. Though this method works well for many, it can also leave quite a bit of work for the decorator. If an image is to go on several different products, for example, the colors will vary on each item unless tweaks are made in the graphics program.
There are also specific programs developed by sublimation printer manufacturers that are specifically designed for its brand of ink and printing system. Functions vary by company, but some offer color chart palette systems, for example, that integrate with CorelDraw or Adobe programs. These programs offer users an entire integrated system from ink to software to hardware.
Raster image processing (RIP) software is another tool for professional series printers that can help with page layout, duplication, insert variable data (names, photos, etc.) into a stock layout, reduce ink usage and provide greater color accuracy. They are generally setup as a next step once graphics have been created. Art is designed in CorelDraw or Adobe Illustrator and Photoshop but, instead of printing directly from these programs, the graphics are exported to the RIP which translates them to the print device.
RIPS differ from the other methods of color management by offering a significant amount of fine tuning. For example, RIP users will perform periodic linear density configurations. Here, sublimation users will print out and heat press a color target, then use a spectrophotometer (a very high end scanner) to read the colors back into the program. This process allows the software to compensate for performance differences encountered using a printer over time. For those who require creating their own ICC profiles, RIPs will often have profiling software available as an add-on.
Substrates and color
In decorating products via sublimation, it is important to realize we are working with semi-translucent dyes. This results in the background color of an object changing the color we are trying to print. While white items are the most common to decorate, white points vary significantly between the different sublimatable items available. Colored garments complicate the situation further and can significantly change how the artwork is reproduced. The result of this is that each substrate requires different outputs to get the same color results in the end product.
With all of these variables, it’s understandable that many decorators have spent a considerable amount of time cursing their sublimation system for not producing the right color. All of that frustration can be avoided. Color management may at first seem like a mystical event that takes place inside our equipment. Once the proper tools and techniques are employed, achieving accurate colors can be just a mouse click away.