How Do I Know What the Colors Will Print Like?

Editor's Note: This is the fifth article in a seven-part series. This content is also available in the white paper, An Introduction to Product Labeling. You may download this very informative guide to product labeling free of charge as a printable PDF file, courtesy of Lightning Labels.


Ouch! — this is an area that is worthy of a 500-page novel all on its own, but we’ll try to paraphrase it here. The first thing that many people don’t understand is that computer screens, desktop printers and commercial printing presses use very different technologies to produce colors. A computer monitor uses an approach known as "RGB" (which stands for Red/Green/Blue) and the colors you see on the screen are all made up of various proportions of those three primary colors. Desktop printers (like the one probably connected to your computer) have their own variations — but most work with a system called "CMYK" (which loosely translates to Cyan/Magenta/Yellow/Black) — yes, the K actually means Black. What this means is that the colors you print are made up of various proportions of those four colors — NOT the same 3 colors your monitor uses to represent the same values. Sound confusing? — welcome to the world of challenges faced by all commercial printers. To compound this problem even further, there are often (very often in fact) substantial differences between monitors and printers (even of the same make and model). It’s quite likely that if you displayed the same file on 10 identical monitors, you would see some variations — and the same applies to 10 printers of the same model. In essence, it’s vitally important to understand that what you see at home (or even at your designer’s office) is NO guarantee of what will come off the printing press.

What’s more (and just when you thought this was already difficult enough), printing presses also use various approaches to producing colors. The traditional large mechanical presses that you’ve probably seen in the movies (commonly known as "flexographic" presses or "flexo" for short) use pre-mixed inks and "plates" to apply the various layers of ink to the material. Conversely, there is a growing family of newer "digital" presses being used that adopt the CMYK approach described above (known as "4-color process" in the printing industry) — each color is made up automatically from the 4 prime colors as it’s printed. Accordingly, there can be substantial disparity between a "flat color" and its 4-color process equivalent. If you’ve heard of Pantone (or PMS) colors, you may think that a single PMS color will always reproduce the same way, but in fact each PMS color actually has two versions — the flat (single ink) version and its 4-color (mixed) cousin. Often, the two versions are very close to identical, but some flat colors cannot be closely matched using the 4-color process and the differences are quite noticeable.

So, now that we recognize that color-matching is a nightmare waiting to happen, the smart approach is to see what the press is actually going to print before going into production — then you at least have the option to make adjustments in the artwork to achieve the look you’re seeking. Ask your label printer for press proofs — depending on the technology they use, these may come at an additional cost but some printers willingly provide them free of charge. Companies with digital presses are far more likely to be accommodating here, as they print direct from the artwork rather than having to make plates.

The key point of this section is that if specific color rendition is an important part of your need, you are strongly advised to consult your label printer for options that will allow you to see the result before going into full-scale production. Print shops typically require you to "sign off" on proofs to limit their liability and exposure — which will come as no comfort to you if the resulting production run has different colors than expected. Always ask to see what the press will produce first.

Continue Reading An Introduction to Product Labeling or Read Part 4 of This Seven-Part Series.