Brands need to know how well a package printer can match their colors on press.
If they are going to invest in an important packaging project, they want to be assured that a printer—and the press—are up to the challenge.
All photos courtesy of GMG Americas
A brand’s colors may appear in a variety of designs, on a wide variety of different substrates. Different substrates will typically have a different surface color as well as different printability. To ensure the same visual appearance, or a very close spectral match of a brand color on different materials, a printer or ink company will perform a color match.
Color matches are typically done for each different printing material, on each different printing process, in a special room called an “ink kitchen” with special equipment.
To perform a color match, base colorants are mixed together in different portions to achieve the minimum color difference from the target brand color. This process typically requires expertise in color matching, knowledge of different substrate types, understanding of color and tone, and understanding fit-for-use criteria such as food safety, fade resistance, adhesion and more. This process not only requires specialized user knowledge of color, but also requires use of specialized ink formulation software.
Ink formulation software contains libraries of color materials. It knows the spectral color properties of each material or colorant, and what will happen when materials are combined. This software is then used to build a recipe that produces the correct color on the correct substrate.
Typically, ink formulation software calculates an initial recipe, which is used to make a small sample of ink, which is applied to the production substrate and measured. If the measured result is not close enough, the ink formulation software will use the additional measured data to update the recipe. Users iterate the process until the color match is acceptable, or they are unable to further improve the match. At that point, the recipe is finalized.
The end result of the final color recipe is the color match: a physical sample that looks as close to the target as possible that can be printed accurately during print production. It’s a “real ink on real paper” test to proof the result.
During the color matching process, “drawdowns” are used to test colors and finally arrive at the color match. A drawdown is a small amount of ink, applied to the expected packaging substrate, that shows what the production spot color will look like. The entire color matching process is done once, when the printer needs to match a color for a specific print condition. Then, the recipe is kept on file to make more ink and perform additional drawdowns as necessary.
To meet the brand’s expectations and demonstrate compliance, printers will typically provide the ink drawdown for each brand color on the substrate that has been selected for the job. As printers work with new brand customers and new partners who use the same colors, they often make additional copies of the final color-matched drawdowns. These additional copies are sometimes called “color prints” or “color reprints.”
Conventional Prints
Conventional color prints may be produced in different ways:
- Sometimes they are created using a small, special printing machine that simulates real printing conditions as closely as possible
- Other times, drawdowns are made using a manual hand-roller
- In some special cases, printers will even use an actual press to make the prints, which can be very expensive
For brand colors that will be varnished or laminated, varnish or laminate may be applied to the drawdown in order to simulate the appropriate effect. However, varnish or lamination in the drawdown process may be slightly different than in production, resulting in some differences in appearance.
To finish a conventional color print, rectangular patches are cut from the drawdown and mounted on a card or sheet. On this sheet, additional job information, such as ink reference number, job ID and customer ID, is written.
These color prints are then sent to all of the supply chain participants—product managers and designers. If the color is not approved, it may need to go back to formulation, where a new color match will be made—with new color prints—for additional review and approval. Once approved, everyone signs off on the matched color, and the printer is required contractually to match it when printing the job.
Click & Create
For the brand and designer, the most important need is to assure that the selected color is capable of being printed correctly and aligns with their expectations or tolerance.
Commonly used color guides provide a loose visual example of standard design colors, but they are not precise and often do not contain the specific colors brands need to check. In addition, color guides are typically printed on different materials and with different inks than what printers will be using for the actual job.
Color differences between the color guide and the final printed job can be significant—and even extreme—when substrate color and printability is not ideal (e.g. brown corrugated board). As a result, these guides are typically not recommended to define and communicate the real target printing color.
Conventional analog drawdowns provide a more accurate representation of final production color, but require special tools and expertise. As a result, they are typically made only in special ink kitchens, and not widely accessible across all partners. In addition, because drawdowns are typically a wet, manual process, they are time consuming to make and are less repeatable.
Fortunately, there is now a digital method that is simple to use and offers much greater repeatability for reprints: color cards. A color card solution lets users create reprints of the color matches, including the substrate color and texture, on a calibrated digital inkjet printer using reliable, wide-gamut inkjet media.
Like conventional drawdowns, color cards accurately show the correct, print-feasible color. Color cards can also be used to validate functional aspects of the design, such as bar code readability, where conventional drawdowns cannot. Digital color cards take just a few clicks, have digital repeatability, and do not require special ink tools or ink expertise. Because no special equipment is required, color cards may be printed anywhere.
For the printer, a physical visualization of a digital color reference is an indispensable tool for setting expectations in advance and managing print during production. Particularly when working with brands, early evaluation is essential to achieve the best possible end results with minimum rework or waste after print production.
Using color cards, printers have an accurate spot color visual for each combination of ink and substrate, even when using different print technologies. Digital color cards help printers meet a brand’s specifications and set clear visual expectations. They can also be used for internal print quality assurance by quality teams and the press operator.
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