KSPS offers two general types of printing. For short-run black and white and color jobs (quantities of around 1,000 or less depending on the job) and variable data printing, we use high speed digital printing. The second type of printing is offset printing. This type of printing is done on an offset press that prints ink onto paper. Offset printing is meant for longer runs 1-, 2-, 3-spot color, and full-color jobs. Electronic document files for offset jobs must be processed through the prepress area. If these documents are designed with two or more colors, they must be created with a computer program that is capable of doing color separations. Some programs do not allow for color separations. Click here to learn more.
Separations mean that a page is created for each of the printed colors used in the document. For example, if you create a document with blue headlines and black body text, we will process a separate page for the blue headlines and another page of just the black body text. These separations are used in the printing process to make plates that load onto a press and ultimately transfer onto paper.
Four-color process printing is an amazing procedure. Few people outside of the printing industry fully realize either the complexity or the different processes required for converting a color photograph for use in a printed medium. In four-color process printing, inks are used together to create new colors. Because process inks act much in the same way as filters, subjects containing several different colors or gradations of colors can be reproduced using just three colors of ink: cyan (blue-green), magenta (bluishred), and yellow. Process yellow absorbs only blue light, magenta absorbs only green light, and cyan absorbs only red light. When yellow is printed on top of magenta, the result is a shade of red. Yellow printed on top of cyan results in a shade of green. In theory, when cyan, magenta, and yellow are printed on top of one another, black should be the result. In reality, the result is a brownish color, because of the nature of pigments. To help compensate for this, black is added as the fourth color in four-color process printing. This process is often referred to as CMYK.
Look at the photograph on the left. You can differentiate hundreds of different colors in it. However, when it is printed only four inks are used—Cyan, Magenta, Yellow, and Black (CMYK). First, a four-color separation is done from a color slide (or photograph). Occasionally, four-color separations must be ordered through an outside source, please allow additional time for this special order. These separations allow us to burn plates for each color used. These plates are the image carriers used on the press that enabled the press to transfer ink to paper. This transfer results in an image consisting of hundreds of thousands of different sized dots, just like a black-and-white halftone, except that now instead of just one black-and-white halftone, there are four colors of ink laid on top of one another. If you were to look through a magnifying glass you can see some of the dots are printed on top of one another, some are printed right next to each other, and some are just close together. The viewer’s mind is constantly blending the dots, approximating the colors found in the original image.
Printing Spot Color VS. Process Color
There are two different ways color can be applied to paper in color printing: spot color and process color. Spot color is a method of applying a premixed color of ink directly to the page. Process color applies four or more standard ink colors in very fine screens so that many thousands of colors are created. Spot color is usually used when a few exact colors are needed. Process color is more useful for printing photographs, paintings and very complex colored images. In some cases, both spot color and process color can be used on the same document. For example, a company brochure may include color photos (process colors) and a corporate logo (spot color). Spot is usually identified by a color system such as the Pantone Matching System (PMS). It is useful for documents that require only a few colors, such as newsletters, brochures and stationery. Spot color is also used to match specific colors very closely. Process color is used when documents are four or more colors. The original image is separated into its cyan, magenta, yellow, and black components. A plate is produced for each color needed. The paper is run through the four stations of a four-color press to accept layers of ink from each plate. Spot colors can be created in a process color printing by overlaying the inks to match a specified color. The cost of printing color documents is related to the number of ink colors used. As process color requires four or more inks, spot color can be cheaper if you use fewer than four colors. Spot color also has the advantage of printing a wider range of clean, bright colors.
