One of the most common questions that we encounter as a commercial printer is “why don't the colors of the proof I saw on my monitor match the colors of the printed piece?” Sounds like a pretty simple question and with today's technological advancements it should be pretty easy to solve. Unfortunately, this is not the case. When comparing colors viewed on a monitor to those same colors printed, it is actually like comparing apples to oranges, with the only thing they have in common is that they are both fruit. So let's dive into this to better understand what is going on
First, let's talk about color models. Monitors and TVs use the RGB (Red, Green, and Blue) color model to produce the colors that you see on your screen. Colors are produced using light and most monitors can produce close to 16.7 million colors.
Commercial printing presses use either CMYK or spot color inks to produce color. The CMYK (Cyan, Magenta, Yellow and Black) color model produces roughly a few thousand colors. All four ink colors are printed onto the sheet one right after another and the combination of the four colors in varying tones produce the “final” colors. This is very similar to how your inkjet or color laser printer works.
The other color model is spot colors based on the Pantone ink system, which is a standardized color system that is widely used in print shops for consistency. It enables a designer in California to spec out Pantone red 195 in a design and sends it off to a printer in New York and the designer and the printer will be on the same page as to what the red will look like once it's printed. Each color in the Pantone system has a reference number to identify the color and the recipe used to produce the color. This way a print shop can contact their ink supplier and purchase the ink that the designer specified. The Pantone system has about 1,867 solid colors.
Cause and Effect
So what causes the difference between your monitor and your printed piece? It has to do with the way that monitors produce color. When a designer or printer sends you a PDF proof and you open it on your computer a conversion takes place so that the design can be displayed on to your monitor. Your computer converts the design from the color model that the design was created in, either CMYK or Pantone, to RGB and when this happens you see on your screen a rough approximation of what your computer and monitor thinks the color should look like. To compound the issue, monitors use light to produce color and printers can't use light to produce color, they must use inks. Inks, when applied to paper, reflect light to produce color. This is one reason why a printed image will always look darker when compared to the same image on a monitor. To further complicate things not all monitors are built the same, so colors will vary from monitor to monitor. To better illustrate this, open an image on a laptop and then open the same image on a desktop computer and you'll see the difference in color, vibrancy, and contrast
Ok, so what to do? There are things that you can do to ensure that you, your designer, and your printer are all on the same page. First, don't go by the color you see on your monitor or what you print off from one of the printers in your office. There are way too many variables to ensure what you are seeing is a good representation of what the final printed piece is going to look like. When looking at the color of a PDF proof view the colors as a general sense of what the color will look like not an exact match. When working with new colors ask your designer to show you the sample chips of Pantone color equivalents. Make sure they are actual physical samples, don't view the Pantone swatches on a computer screen. Also when viewing swatches play close attention to coated and uncoated swatches. Letterhead, envelopes, and most business cards are printed on uncoated stocks so you want to look at uncoated Pantone swatches. Marketing pieces like postcards, brochures, and flyers are printed on coated stocks so with these items you want to look at coated Pantone swatches. Look for either a U or a C after the Pantone reference number and that will tell you if you are looking at an uncoated or coated swatch. Most print designers have Pantone color guides that they can use to show you what the ink color will look like once printed.
For colors that can't be achieved using the Pantone matching system or for designs that are not cost effective to print using spot colors; like designs that have 3 or more colors or that use full-color photos, you'll have to look at using four-color process printing which uses the CMYK color model. When using four-color process most printers can provide a hard copy proof. The proofs themselves are not printed from the actual press that your job is going to be run on as it's too costly to set up a press to run just a few samples. Most commercial printers have specific proofing printers, these are usually very high-end inkjet or laser printers that are specifically designed to output hard copy proofs. These are much different
One of the best things you can do to avoid unexpected color issues is to work closely with your printer and designer to ensure that everyone is on the same page. Your printer is going to be the most knowable about putting ink on paper. But there are limitations to the colors that commercial printers can reproduce, especially when it comes to colors you see on your monitor. It's always best to talk to your printer about color before moving forward with a new print project to help better understand what the final printed version will look like.