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Color Management Basics Every Product Decorator Should Know

Posted: 6/21/2018

Color is both an art and science when it comes to digital product decoration. The art comes into play when you’re designing what to put on your product. The science comes in during the print and press process.

Understanding how color works in a digital print environment is essential to success in sublimation. Though color science can be complex, here are some basic concepts that will help you achieve great color output and repeat business.

What is Color Management?

The colors you see on your screen will never match the colors in your prints exactly. This is because the colors on screens are generated by combinations of three colors: red, green and blue (RGB). Conversely, digital printers use anywhere from four to eight ink colors to reproduce the image from your screen. CMYK (cyan, magenta, yellow and black) is the standard for four-color digital printing.

Computer monitors emit color as RGB light. Although all colors of the visible spectrum can be produced by merging red, green and blue light, monitors can display only a limited gamut (range of color) of the visible spectrum.

Printed products absorb or reflect specific wavelengths of light, unlike a screen that emits light. Cyan, magenta and yellow pigments or dyes serve as filters, subtracting varying degrees of red, green and blue from white light to produce a selective gamut of spectral colors.

As you can see, there is marked difference in how both types of color generation work. One is additive; the other is subtractive. In digital product decoration, you design in an additive environment (RGB), and then the printer and software has to convert those colors to work in a subtractive environment (CMYK). Color management – or color correction - is the process of adjusting this color transformation so that you can produce the best quality results on your substrate.

Challenges Specific to Sublimation

With dye sublimation, there is another element of the color control process that must be addressed. When a dye sublimation transfer sheet is heated and pressed onto a substrate, the ink turns into a gas that bonds with the polymers of the substrate. During this “gassing” process certain colors will shift, so the finished product will not look like the original image on the screen.

You may also notice that colors of the ink printed on your transfer paper are very different from the final image that is created when heat and pressure are applied. This is because of the chemical characteristics of the dye sublimation process, and another reason why color correction is needed.

With sublimation, these issues need to be addressed for each individual printer and ink combination. In extreme circumstances, color correction may be needed for every combination of printer /ink/substrate and transfer paper. However, extensive testing has shown that in most cases, good-quality transfer paper does not affect the final color. This is why we recommend that you only use high-quality paper.

Color Management Basics

Now that you know why color management is necessary for sublimation printing, let’s look at a few ways this is accomplished.

ICC Profiles

An ICC (International Color Consortium) profile is a set of data that ensures that when a specific color is selected on the computer screen, the designated color is consistently and correctly delivered on the substrate. Think of it as a color-matching program, since the screen color rarely produces the same color output. A profile creates a link between specific screen colors and specific output colors. It doesn’t change the color, rather it ensures the correct output for a given input.

Color correction profiles for dye sublimation have their own unique challenges.

To use this method, you must work with ICC-compliant graphic software (e.g. Photoshop, Corel). The profile will be placed in the output stage of printing and the manufacturer’s print driver will be set to ‘No Color Adjustment.’ This setup will color correct the image and then send the data to the printer without affecting the colors further.

Color correction profiles for dye sublimation have their own unique challenges. Under normal profile creation, when a printer has printed out the color swatch for testing, the profiling software knows how to adjust the colors to print out the correct ones. When a dye sublimation transfer is pressed onto a substrate, the ink turns into a gas, and while in this state, the color properties change.

This change during sublimation can be quite dramatic (e.g. some blues look like green on paper), and it is, therefore, impossible to judge whether the print is correct or not until it is sublimated onto the final substrate. It is necessary to create custom sublimation profiles and print management applications of these profiles to create the correct sublimated color, not the color on the printed transfer.

Custom Print Drivers

Custom print drivers are programs that have color correction built into the printer control system. The advantage of these programs is that color correction is performed at the print driver stage, and they are generally easier and less technical to use than an ICC profile.

For Virtuoso HD Product Decorating Systems, Sawgrass offers Virtuoso Print Manager for SG400, SG800 and VJ 628 printers. Virtuoso Print Manager makes getting great color output easy with CorelDraw, Adobe Photoshop, Adobe Illustrator, Silhouette and CreativeStudio design software for both Windows and Mac OS.

Edit the color in the color tab of Virtuoso Print Manager.

The software’s integrated RIP-like tools help streamline production with an advanced array of features, including job and image nesting, hot folders with customizable presets, multilingual user interface, file- and web-to-print workflows and more.

Additionally, Virtuoso Print Manager enables you to select specific transfer papers, inks, color modes and substrates, which the software will take into consideration while processing the file from RGB to CMYK. With these custom settings, getting the right colors are very easy.

Using Virtuoso Print Manager

Raster Image Processor (RIP)

More technically savvy product decorators may choose to use Raster Image Processing (RIP) software, which includes ICC profile creation capabilities for managing colors. Simply put, RIPs convert images into individual dots (rasterizing) and sends these rasterized files to the printer.

The process of creating ICC profiles from scratch is time consuming, requires a good understanding of color science and is an artform in itself. It begins with printing a linearized color pallet. A spectrophotometer is then used to measure the colors. From these data points, the software creates an algorithm that calculates the color space and generates the ICC profile. Various types of images are then printed on a variety of substrates, and the profile is meticulously adjusted to optimize the final result.

RIP software also handles workflow tasks, such as nesting images and batching or queuing files to print. RIPs are available from a number of software companies, including Wasatch and Ergosoft. Sawgrass recommends the use of Wasatch SoftRIP with the VJ 628 for users looking for a more advanced color management and production solution.

Easy Tricks of the Trade

As a digital product decorator, there are a few things that you want to make sure you do to ensure your colors will sublimate as you expect:

  1. Apply the Correct Color Management Tools: Each of the options discussed above have specific ways to apply the software to your prints. Get trained on how to apply them correctly and make sure you do so with every print. For example, if you are printing a design from Photoshop select Virtuoso Print Manager as the printer, not the SG400, SG800 or VJ 628 option that may be in your dropdown list, when printing your images. Selecting Virtuoso Print Manager as the printer will open the color management software where you can make your selections for paper type, substrate, color mode, etc.
  2. Always Design in RGB: Most design software has a set color mode for the design space of the file you create. They are usually RGB and CMYK. We call this defining the color space. When working with sublimation, you need to activate a specific RGB profile to produce accurate colors, unless working with a RIP, which uses CMYK.
    Select RGB color from the Image and Mode tab when designing for sublimation.
    For example, many graphic artists design in CMYK color mode because this is the most appropriate for commercial printing. Because sublimation requires RGB, these files need to be converted upon importing into your design software. The reason for this is that sublimation profiles are built to convert RGB colors to CMYK output, not CMYK to CMYK (unless using a RIP). If you try to print a file that is CMYK, the conversion will not work correctly, and the colors will be off.
  3. Print and Press Color Charts: Whether you are using an ICC profile or a custom print driver, we suggest you create a color chart by printing out and sublimating an entire palette of colors to a pure white substrate. This creates a visual reference that you can refer to and show customers.
    Sawgrass’ ColorSure palette is included with Virtuoso Print Manager, and those using an ICC profile can create a simple palette of their own to use. The printed chart will show the exact color that is created via sublimation (plus the RGB settings), so both you and your customer have an accurate reference when choosing the proper colors for the image being created.

    Though the colors may not look the same on the screen as they do on the final substrate, by choosing the desired colors from the chart, you are assured that the output will be a match every time, regardless of what is displayed on the computer monitor.
  4. Consistency is Key: Any change in any of the variables in the create, print and press process will impact your final output. These include substrates, sublimation paper selection, pressing time, temperature and pressure, as well as color management techniques. It’s necessary to experiment and test until you generate the desired results. Then, establish a set of standards to work by, with the full understanding that a change in the standards can lead to a change in the appearance and quality of the final product.

There is much more to be said about color management, but these basic concepts should help you gain a better understanding of what’s going on when you create, print and press – and how to get the colors you want.