Coated or Uncoated ink?
Good question. To find a quick answer, scroll down and read the summary below.
Let’s start here: “coated” or “uncoated” refers to paper characteristics, not variations in the ink. The formula (ink mix recipe) that we printers use to mix the ink is the same regardless of whether we’re looking at a coated formula swatch book or an uncoated swatch book. (See picture above) The primary reason that digital ink swatches are labeled with “uncoated” or “coated” are to provide an approximate reference for how a specific color will appear on different styles of paper. I know, it can be confusing. The fact that these Pantone labels remain within Adobe swatch libraries is baffling, considering the disparity between how color appears in the digital realm vs how it appears as ink on paper. The computer does a poor job representing spot color, especially when that color is supposed to represent paper texture it will be printed on. A computer screen can’t accurately do that. So it can be confusing for the new designer who is only referring to the computer swatch selections. As straight-forward as this may sound to some of you, there’s really not much clarification out there on inter-webs, so we thought we should address it.
What am I talking about? If you have ever perused swatch options within an Adobe application like Illustrator, you’ll find color swatch collections (swatches > open swatch libraries > color books) named “Pantone+ Solid Uncoated” or “Pantone+ Solid Coated.” Or better yet, if you are referring to a physical, real-life pantone swatch book, you’ll also notice that it will be labeled as Pantone “uncoated” or “coated” or even “matte” if you have an old book kicking around. (If you are looking at the real-life-paper Pantone swatch book, you will immediately notice that the designation of “coated” or “uncoated” refers to the paper the swatches are printed on, not the ink - it’s easy to understand if you have these books in hand) The individual colors within those specific books (or swatch libraries within your Adobe software) will have a corresponding suffix such as Pantone 032U (U for uncoated), Pantone 032C (C for coated), etc.
So what does this mean? I know you are thinking: Ink is a liquid, right? How can you coat a liquid? Huh? Yup! You can’t! But you certainly can apply a coating to the paper. Or hit it with extra calendering during the manufacturing process to make the sheet super smooth. So? Well, the smoother the stock, the more light reflective it is, also the smooth surface is less porous which results in a less absorbent substrate. Which means the ink pigments don’t have to fight to be seen. They get to rest on the surface and reflect their brilliance to the world without sinking into the paper fibers as they would when the sheet is not coated (a “saturated” look). So, you can imagine that ink color would be highly influenced by paper it is printed on. A light color ink printed on a brown kraft grocery bag will not look as bright as if it were printed on a “shiny-smooth” bright-white paper.
In short: a specific Pantone ink mix (formula) will look very different on different kinds of paper.
Whoa, hold on a minute, if Pantone knows that ink looks different on coated paper and uncoated paper, then surely the distinction of Uncoated vs. Coated refers the color formulation mix for a given color so that it appears the same regardless of what kind of paper the ink is printed on, right? Mmm, good thought. But it doesn’t work that way. The ink mix is identical. My explanation above only scratches the surface. There are many, many variables that can influence the way ink appears on different papers. Color, paper composition, finish, different paper manufacturing equipment, moisture content of the paper, print method, print machinery, etc. Pantone is only providing a reference to illustrate the major influencing factors that will affect color appearance. Coated paper vs. uncoated paper is a biggy when it comes to how the color is represented, so two different books are a good place to start when picking a color for your job. Otherwise Pantone would loose their shirts if they made swatch books that represent every possible color combination on every paper combination. Not to mention, if there were enough pantone swatch books to cover all paper / ink combos, it would really piss off printers. It would cost a small fortune to update a print shops’ swatch book collection when new colors mixes were introduced.
So, start with the major category of how your ink color choice will look on a coated (shiny) surface vs. an uncoated (roughish) surface. Then talk with your printer to discuss what other variables may effect the color choice. There are always ways to customize the ink mix in order to get the results that you are hoping for. Remember, the mix is the same regardless. Your printer can help tweak the ink mix according to your needs. Talk to them. Most printers enjoy discussing these things with their customers.
As far as how a spot color swatch appears on your computer screen, well, that’s a tough one. It’s always best to look at a physical ink sample that is printed on the paper that you have chosen for the job. Spot color represented on a computer screen is only a rough approximation. Of course the way your computer simulates color is much different than actually mixing liquid ink together to build color. Always look at the real deal, and talk with your printer if you have concerns. We’re going by standardized ink mix formulas, not computer screen calibrations.
I hope this helps.
TO SUMMARIZE:
1. “Uncoated” or “Coated” refers to the paper, not ink. Ink itself is not coated or uncoated.
2. An ink formula for a given Pantone Spot color is the same regardless of the suffix after the number i.e. Pantone 1797U is mixed the same as Pantone 1797C, or Pantone 1797M.
3. Printers are nerds and love to talk to you about this stuff. Ask them questions if you are not sure. Together you can come up with a strategy to best meet your expectations for your print job.
Happy inking, inksters.