When you create a color swatch with Illustrator you may need to know some easy settings which the software proposes. Particularly the difference between Spot Color and Process Color is really important for a good printing result. Moreover, properly choosing the type of color between these greatly affect the final costs of the printing whole process. In this article we will see which options are the best for the job, why, how to properly manage Illustrator Swatch Options window, color options and book library.
In order to better understand the different kind of color options in the swatch manager we have to inspect first a couple of important related issues:
Color models, such as RGB or CMYK, describing the colors we see and work with in digital graphics, and Printing methods, such as offset lithography or digital printing.
An Overview on Color Models
There are several models used to describe the color scheme: RGB, CMYK, LAB etc. Each model was created for specific purposes and has certain advantages over the others. Converting between the different models is generally done by a relatively simple mapping and it could be performed directly via software in case of professional ones (for example, Adobe Creative Suite software, Corel software, QuarkXpress, etc.)
By the way, the main common used color models are two: CMYK, a subtractive method, used for printing and based on inks use, and RGB, additive color model used for computer displays and based on light transmission.
It is important to choose the right color model for the job, i.e. if you are going to print your graphic work you should use CMYK method. If your graphic creation has been thought for a screen purpose then you should use RGB mode.
Today’s digital printing methods do not have the restriction of a single color space that traditional four-processes do. Many presses can print from files containing images using either RGB or CMYK modes. The color reproduction abilities of a particular color space can vary and this may depend from paper, inks, gamut (the color range availability of a color model). The poorest gamut vibrancy of the ink colors may give unexpected results if you try to print RGB images as they were CMYK ones. RGB is for screen display and has an extremely wide gamut. Using RGB for printing is a gamble: if your image RGB gamut stays inside the CMYK one the image will be printed in the same way that if you had converted it. On the other hand if its RGB gamut exceeds the destination CMYK gamut colors will be different from the expected.
CMYK or “Process Color”
In commercial printing the procedure to print full color images such as photographs, brochures, business cards, leaflet, and so on and so long, is based on the CMYK color mode. This technique, which considers a mesh of four color (Cyan, Magenta, Yellow and K that represent a Key color), is called four-color-process.
The CMYK mode is based on the subtractive method where the process begins with white, the white canvas of the paper, and ends with black. By adding color, one over the other all three secondary colors, the result become darker and tends to black.
Where all three inks overlap, almost all incident light is subtracted, producing a weak black. To enrich this poor black a fourth key color, the black, is added as additional ink.
RGB is an additive reproduction process which uses light to display color. The additive primary colors red, green and blue beams produce all other colors. Combining them each other produces the additive secondary colors:
- Red + Blue = Magenta
- Blue + Green = Cyan
- Green + Red = Yellow
Combining all three primary lights in equal intensities, Red + Green + Blue, produces white.
The RGB model is extremely important to graphic design because it is used in computer monitors.
Which Printing Methods Fits to the Job?
Nowadays the most common ways of creating printer products are offset lithography and digital printing.
Offset is the most common high volume commercial printing technology, applied to newspapers, magazines, brochures, stationery, and books. It is based on four plates. Each plate used to compose the final image represents a color. The results is of impressive quality, images are neat and sharp.
Offset printing offers the most flexibility. The creativity is free to experiments a wide range of materials, feeling the differences between papers, using plastic or metal surface, print on fabric depending on the best suitable printing support and sensations that the designer want to move inside his target.
The cost convenience comes with high volumes because preparing plates itself has a cost that could be too high to be covered if you need few pieces to be printed. The more volume the lower costs.
In those cases where you need few copies of a graphic products the best solution is the digital printing because is featured by fixed cost per copy, fast production and, with modern printing and inks, decent accuracy. It is the closest solution for a cost/benefit ratio. It is easier and time saving because you don’t need to make plates and expensive color proofs.
Digital printing is intended for a limited number of copy. The color mixing is automatic so this printing method ensure a higher adherence to the project because you don’t have to measure ink mix every time. That’s why color proofing are less expensive. In addition, because you don’t have to produce plates every little changes you apply to the design, it is the right method to use to create personalized printing, for example greeting cards, customized advertising or letters.
Defining Color Type
A Spot Color (or Solid Color) refers to a color printed with its own ink. The range of available spot color inks is nearly unlimited. There are several industry standards in the classification of spot color systems, but the most famous is PANTONE®. Other spot color systems include TOYO, DIC, ANPA etc.
Each color is not composed, each time, by the CMYK mix but is considered like a basic one.
Spot color can also be used to refer to non-standard inks, may vary from pastels to fluorescent and metallic, as well as clear varnish, or anything else that requires its own printing plate.
Because of this procedure the printing costs increase. By the way the accuracy of the color matching is extremely high. The use of spot color is highly recommended for Company Logo or Institutional printings.
A Process Color consist of Cyan, Magenta, Yellow and Black (CMYK). These four inks can be mixed together to create a full spectrum of colors in a document. Because of the four inks are mixed to obtain a color the result may vary, depending on inks quality, printer accuracy, operator ability, paper or any other printing support.
As the name may suggest Global Process color is a Process color which goes global. It is based on process color method, so with CMYK separation and plates creation, BUT it retains a link with the objects, acting as a spot color. This means that the total number of plates coming from a Global Process file will be four, you will have the ability of specify color values but if you vary the tint you also update all those objects which are using that tint all at one.
Spot, Process and Global Process in Illustrator
We have defined till now all elements to better understand the Swatches Option in Illustrator. Let’s go now to inspect that palette and how the different type of colors look like.
Go to Swatches options>Opens Swatch library>Color books.
A list of standard book in the color industry is shown. If you choose to open, for example, the Pantone Solid Coated library a new palette that includes all those colors will opens.
Choosing a color from a library you apply a Book Color. A book color is of Spot type.
No mix different books in a single project! This is an important thing to remember. So, for example you must avoid using coated and uncoated together because each books has been developed for different dedicated intents.
You can see here following an example of how appears the Swatch Options window when you pick a color from a book library. If the color is a Pantone, the swatch name is grayed out, the type is Spot and you can’t modify it, you can only change the mode.
Anyway you can turn this same color in a CMYK Spot Color just changing its type from the drop-down menu. It becomes a Spot color where you can see the CMYK percentage.
You can now change the CMYK values and the color name but you need to have clear in mind that, changing the values, you lose the standard.
From a printing point of view you are asking to your printer service a plate for that new color, so you are increasing the printing cost.
Illustrator identifies in the Swatches palette the Spot colors with a small white triangle in the color sample corner with a dot inside.
Spot color maintains a link with all the objects using that color in the document so that you can vary the tint without varying the color. If you replace that color the change will be applied to all those object that use the color.
You can turn the Spot Color in a Global Process one just choosing Process form the drop-down menu and leaving the “Global” option activated.
As the Spot color the Global process maintains a sort of link with all the objects using that color in the document.
The Global Process Color allows you to create a single color swatch in CMYK mode that you can update having it applied globally.
For instance, if you apply the same global color to many objects in your Illustrator document and then you decide to change the color, you simply edit the global color and everything on the page updates.
This is useful when you want use just few color swatches to the document varying its percentage to make different gradients.
The Global Process Color is identified with the same white triangle as the Solid but without the dot.
Finally from the same Swatches Option panel you can turn the Global Process in a simple Process just unchecking the Global box. Process Colors do not automatically update throughout the document when the color is edited.
Illustrator remove from the color miniature the white dotted triangle.
The Global Process is not really different from the Process because it is a result of CMYK mixing as well. It is a convenient arrangement because of its behavior such as a spot color.
While some Spot Colors can be simulated well, there are many that look quite different. Particularly green and orange tints are tricky and may vary a lot. Pay attention that this not necessarily means a quality loss.
As the quality of the resulting color conversion is very subjective, the designer can make decisions using the PANTONE® COLOR BRIDGE™ guide, comparing the different result between spot and process.
Illustrator, as many high level graphic software, leaves to the creative the choice, depending on the use and on the customer requests. Big Companies have logo specification which requires Pantone colors where other just use the Pantone standard as indication about which CMYK percentage the graphic have to use.
When is Better to Use a Spot Color
As we said, generally spot color are specific colored inks following formulations that are designed to be print alone, rather than to blend with other inks.
The more spot colors used, the more film and plates are needed, the higher are costs.
To maintain a good cost/benefits ratio you may use only one to three different spot colors in your job, otherwise it would be better start to prefer process colors.
So here a list of occasion where using a spot color is an advantage:
- Publications uses no more than three colors.
- Pantone color specification required to exactly match a big company logo color.
- Use of particular inks such as metal, pastel, varnish tints.
- Colors that can not accurately reproduced with CMYK Process inks.
When to Prefer a Process Color
Talking about how many colors is best to use in printing is obvious now that Process Colors and Global Process are in this case the same thing because both are based on CMYK blending.
So a Process Color method should be preferred when:
- Publication uses full-color photographs.
- Publication needs to reproduce more than three spot colors.
- To produce various hues and shades depending on the type of paper.
When Using Both
Sometimes it could be even better use both, spot and process method, in the same job. This happens when, for example, you have to print an institutional brochure or an annual report where you have to reproduce the exact company logo color and multi-color graphs, charts and photography.
So you can apply the spot color to the logo and process to the other elements of the page.
Remember that this goes to increase your costs because you will get as result four plates (CMYK) plus a plate for each spot color you may add.
To Sum Up
Using a Spot color means a new printing plate use, increasing printing costs.
Process Color is based on a CMYK mix and creates a single swatch.
You can apply Global Process Color, still based on CMYK inks, to globally update colors such as Spot one without requiring a new plate and saving money.
The method you are going to apply will affect your printing costs and results.