Color Printing Basics

Full color printing has changed very little since its appearance in the 1890s. The process of separating the print job into four colors, cyan, magenta, yellow, and black is still the foundation of all color print jobs.

In order to print a color photograph, the picture is converted into a series of dots. The finer the dots, the sharper the image will be. These dots were created at one time by taking a picture of the picture or negative through a fine screen. This screen would break the picture into dots. To get the four colors needed to reproduce the picture in color, filters were placed between the picture and camera. These filters would allow only the color desired to pass through to the film. The result was four negatives.

The ease with which this is done has been simplified by the computer and digital photography. A digital photograph is already broken down into dots called pixels. A computer program, such as Adobe Photoshop, can analyze a photograph and create the separate files needed to make the four halftone screens the printer needs. If your photograph was produced from film, a quality scanner can convert the photograph to digital format.

From this stage the process of printing in full color has changed very little. The four colors must be laid down one at a time. A printer includes register marks along the edge of the print job, so that each layer of ink goes down precisely on top of the other layers. A four color press is really four presses in one. The paper goes through the cyan press, then the magenta press, then the yellow, and finally the black. The result is a full-color product.

Color Printing Q&A

What is resolution?

Resolution can be confusing. SPI (samples per inch) is a measure of image resolution. This sample information tells the computer how to display a picture. It also tells the desktop printer how to print a picture. Some software uses PPI (pixels per inch) and others use DPI (dots per inch). PPI tells you how an image will display on a computer screen. DPI can give you an idea of how sharp an image will be on paper. But LPI (lines per inch) is the measurement used by a printer to determine how many dots will print on a line. LPI is equivalent to the halftone screen. Because software tends to use PPI and DPI as though it is the same as SPI, assume that the higher PPI or DPI a photograph has, the better it will print.

What is the minimum resolution my photograph should have?

The minimum resolution is related to the size of the printed photograph. The larger the photograph the higher the resolution must be. If a photograph looks grainy on your computer screen, it definitely isn’t adequate.

The photograph displayed so well on my screen. Why doesn’t it look as good when I print it?

Screens don’t require as many dots per inch to display a clear picture. When a picture is transferred to paper, more dots are necessary. Of course, good commercial printing companies, like the ones featured here at PrintingChoice.com, all use the highest quality printing presses to print your job. Make sure that your file resolution is at least 300dpi so it will look good in print, otherwise even if it looks good on your screen, you may end up with blurry prints.

Why are register marks necessary?

Register marks allow the printer to see if the paper is lining up correctly. How many times have you seen a magazine cover with a slightly fuzzy appearance? This fuzziness comes from the colors being slightly out of register with each other. When the colors line up perfectly, the picture is sharp.

Do I have to submit digital photographs?

Ask the printer. Most printers have the ability to scan and convert photographs into the digital format that they prefer. Any printer that offers their services online should be fully digitized.

Color Printing – Conclusion

Full color printing costs more for obvious reasons. The job requires four colors of ink and four separate screens. But the advantages of choosing full color are just as obvious. Full color brochures, pamphlets, postcards, letterhead, etc. reflect a successful business image. This simple overview of full color printing basics should help you feel more comfortable as you consider your options.

Be sure to check out our printing price search here at PrintingChoice.com so you can choose between the top quality, yet lowest-priced color printing companies on the web!