Posted on February 1, 2010 - by Lisa Nalewak

Spot Color – When Color Saturation and Consistency is Key

This is the 4th in a series of articles on Graphic Design specifically written for Business Professionals.

Spot Color refers to a printing process that uses specially colored inks to attain a very specific color when printed. Each individual ink is a unique color, and is a careful combination of pigments that are mixed in very exact proportions each time the ink is created, so that the ink is always the same color when laid down on paper, or on other substrates. Unlike process color, which uses cyan, magenta, yellow and black inks to lay down dots on paper that, when viewed from a distance, can create the entire color spectrum, spot color inks are usually laid down on paper to represent its color, and its color only (or a screen thereof, which is a lighter version of that color).

There are a number of companies that produce spot color inks. The largest and most well known in the design industry is Pantone (www.Pantone.com). Pantone has created a color matching system that is used by designers and printers to guarantee exact color matches whenever an ink is mixed and printed. Pantone sells Pantone Matching System (or PMS) booklets and “color fans” that include chips of all the different inks they produce and how they look on coated and uncoated stocks, so a designer can use these books to see a color when it’s printed, and can show a client how a color will look in “real life”, rather than how it looks on an electronic proof of a piece viewed on a monitor (monitors use RGB color, which will look different than the actual printed color – see my post on RGB color for more information).

These booklets also contain the “recipe” for the colors, so printers know how to mix the inks correctly by using specific amounts of Pantone supplied pigments. Using one of these books to pick an ink color is very much like going to the paint store and picking a paint chip of a color you like, and then bringing it to a person who then mixes it following a very specific “recipe” for getting that exact color paint, every time.

Spot color inks can achieve special effects like neon brightness or a metallic sheen by adding special compounds or pigments to the ink. These effects are not achievable using four-color process (or CMYK) printing. Whenever you see neon ink, or ink with a metallic sheen, it was created using a spot color ink. Whenever you want this sort of effect in a printed piece, you must use a spot color ink.

You can mimic a standard spot color (one without special properties like neon brightness or a metallic effect) by using a combination of the four process colors (cyan, magenta, black and yellow) to achieve the desired color. There are two issues with this, however: 1) color saturation and 2) color consistency.

Color saturation is a measure of a color’s “brightness”. There are some pigments (particularly blues) that when used in a spot color ink are far brighter and more vibrant than can be achieved by trying to mix the same color using the four process colors inks. For example, the bane of every designer is a pantone color called Reflex Blue. As a spot color, it is a vibrant, deep, indigo blue. When printed in it’s four-color equivalent, it’s a light navy blue. The two look very different. There is no color combination using CMYK process inks that can attain the equivalent of Reflex Blue. If you want the Reflex Blue color in a printed piece, you will need to use the Spot Color ink to achieve that result. This is very difficult to explain to someone who doesn’t understand the limitations of four-color process printing versus spot color printing, without seeing the two results printed side-by-side.

Color consistency is how similar a color looks each time it is printed. When process color inks are used to mimic a Spot Color ink, there can be variations in the way the resulting color looks. For example, if the pressman recently filled the magenta ink well on the machine, but the cyan well is getting low, the resulting color may run “hot” on magenta, meaning that the color will have a very full amount of red in it and look “more red”. If you switch the amount of inks in the wells, and the press is full on blue but is getting low on magenta, your color may run “hot” on cyan, and the color will have a bluer look to it. In addition, a pressman will adjust the relationships between the intensities of the four process colors before starting the printing run, so that the resulting printed pieces are as balanced as possible (reds print red and not purple, blues print blue and not green, etc.). While the press is operating, the pressman will also do their best to maintain the color consistency from the first piece to the last. These tweaks during the print process mean that each time a job is run, there is the opportunity for the colors to be balanced differently than in previous runs. If you compare, side-by-side, the same printed piece run two different times on two different four-color process presses, it is not uncommon to see slight differences in colors that should be the same. In contrast, spot colors will almost always look exactly the same.

Because spot colors can have unique color properties, are generally more vibrant than colors created using process color inks, and are more consistent when printed, they are used most frequently to color corporate identity materials. For some companies, particularly large companies with very well known retail brands (McDonald’s, Nike, Coca-cola, etc.), it is extremely important that their brand always look the same. It would not do to see a McDonald’s logo where the red looked a little bit more purple than it should, or have Coca-Cola’s red seem a bit more like an orange. To ensure that these colors always look as consistent as possible, designers are required to define specific spot color inks for these elements when creating art for printed collateral.

Spot colors are also used when consistency is important in evoking a specific response. It is wise to use the same, vibrant spot color blue on an investment firm’s annual report each year, creating a feeling of stability and consistency that is important to a company like a financial institution. It is a good idea to use a spot color for the sunny yellow portion of a travel company’s letterhead, ensuring their customers have the same emotional response each time they interact with communications they receive from that travel company.

Spot colors can also be printed in “screens” or “halftones”, meaning you can print the color in a lighter version of itself by adding spaces between dots of the color to let the paper background show through. On a white piece of paper, a Kelly green spot color ink printed at a 70% screen (meaning 70% of the background will show through the area the ink is printed on) will look like a light mint green. A bright red spot color ink printed on white paper at a 60% screen will look pink. You can sometimes use screens to make a piece appear like it was printed with more than a single spot color ink (like a Kelly green and a mint green) by using different screens of the color in a design.

You can also overprint spot colors, meaning you can print one spot color ink on top of the other during a press run to get a new, third color. In general, you’ll get the best overprint results by using screens. For example, you can use a screen of a spot color yellow and a screen of a spot color blue and to get a green where they overlap. Overprinting is a fairly advanced production technique, and your designer needs to be very knowledgeable about spot color printing in order to realize expected results.

When graphic designers create graphics to be printed in spot-color, they “set” the colors for the graphics they create using “custom” inks that are defined inside their graphic design programs. When using Pantone inks, they set a color for a graphic by picking it’s color code out of a list their design program will display and applying it to the selected graphic. This way, when a printing press outputs these files as printed materials, it understands that it must lay down that specific spot color ink in the areas the designer defined to include that spot color inside the graphics file.

What does this mean to me?

So what things do you need to keep in mind about spot color that’ll make your life easier when you purchase design services or printing services, or need to use or modify art you already have on file?

1)      Spot colors allow you to achieve special effects, like neon colors and metallic inks, in your printed collateral.

2)      Spot colors are generally more vibrant than colors created using a combination of process color inks, so they are good to use when rich and bold color adds to the overall effect of a design.

3)      Spot colors allow you to maintain excellent color consistency across multiple printed pieces and different print runs or output methods.

4)      Because of the special properties of Spot Color inks, they are best used when color vibrancy and consistency are very important in the pieces you are printing.

5)      Spot colors are generally more expensive to use than four-color process colors.

6)      You can add spot colors to four-color process printing, as 5^th, 6^th and even 7^th and 8^th colors in a print job to embellish a piece, or add special effects (like a metallic rule line on a page with full-color photographs). The more spot colors you add to a press run, the more expensive the final piece.

7)      Spot colors can not be used to achieve full-color printing or inside of full-color graphics (for example, you can’t make the navy blue jacket someone is wearing in a full-color photograph Reflex Blue instead by “applying” that color to the jacket.)

8)      You should NOT use spot color art set up for printing in any document you’re creating to be displayed on an electronic device (PowerPoint slides, web graphics, etc.) It’s best to convert these graphics to their RGB equivalents so that they display correctly and so you can tweak the colors to most closely match their Spot Color equivalents.

9)      SPOT COLORS LOOK DIFFERENT PRINTED ON PAPER THEN WHEN VIEWED ON A COMPUTER SCREEN. When an able computer application automatically converts Spot Color art you are viewing to its RGB equivalent in order to display it on your monitor, the colors will look different than they do when printed. In some cases, the color variation will be very noticeable, while in other cases it’s not as noticeable.

10)  SPOT COLORS LOOK DIFFERENT PRINTED OUT ON A LASER OR INK JET PRINTER THAN THEY LOOK WHEN PRINTED BY A PRINTING PRESS. That is because your desktop printer is converting the spot color ink to its CMYK equivalent for output, and as I explained above, some spot colors translate very poorly to CMYK color because CMYK inks can not approximate the vibrancy of spot color ink pigments.

11)  It is imperative that you check the spot color in a booklet prepared by the ink vendor so you can see the exact color it will be when you print it. DO NOT RELY ON YOUR COMPUTER SCREEN OR YOUR DESKTOP PRINTER to proof color for spot color artwork. I should really repeat this as point #12 too, because it is a very important thing to remember. It’s an extremely common mistake people make unknowingly, and then wonder why their printed materials don’t look the way the expect them to look when they get them back from the press.

How to handle Spot Color artwork for electronic display

Yes, this paragraph is a repeat of the one from my RGB and CMYK posts, but I’ll say it again: A good designer will ask you how you plan to use the art they are creating for you, and then will deliver you the art in multiple file formats and in multiple color formats that are matched as closely as possible. In this way, they assure that you have the art you need for any application, whether it’s print or electronic so you don’t experience color surprises down the road.

If you have Spot Color artwork that you need to display electronically or have printed in process color, and you don’t have it in RGB or CMYK format, a knowledgeable designer will be able to convert your Spot Color file to RGB and/or CMYK for you. In most cases, color “rebalancing” will be necessary. The graphic quality of the art you give your designer will also affect the outcome. Higher resolution images generally give better color conversion results.

How to handle Spot Color artwork for Process-Color printing

Because the CMYK equivalents of Spot Colors are often quite different than the Spot Color inks themselves, you must be SURE you want to print your Spot Color artwork using CMYK inks, instead. If you are, ask your designer to color balance the artwork so that when it prints, it’s as close a match as possible to the original Spot Color inks. Some spot color inks translate very poorly to process color (blues, purples and reds are the worst) others aren’t quite as bad, though you will always notice a difference, no matter what the color (unless it’s cyan, magenta, process yellow or process black). An experienced designer will understand how to do this, a bad or inexperienced designer will not.

Continue to the 5th article in this series.