It’s about the screens. Well, who cares about screens? If you are purchasing color offset printing services, you need to be aware of the differences between the 2 different screen technologies used in commercial printing. It affects the quality of all your color prints. You may know some of these things, but most people who buy prints don’t know what you’ll learn in this article. This is a bit technical, but stick with it because you may want to make some changes to the way your print is printed. Then let’s get started.

Is that how it works. Your files go to prepress where they are checked for technical errors before being turned into screens for printing; it is the first step in the process. The client files then go to a platemaker to be processed and then transferred (offset) onto 4 different metal plates, one each of cyan, magenta, yellow and black. Each platen transfers the ink to a rubber blanket, and the blanket moves the ink over the paper.

Most commercial printers use conventional AM (amplitude modulated) line screens, which are dots arranged in a rosette pattern to create images. That means each screen plate has to line up perfectly at very high rotational speeds of the press cylinder to maintain sharp registration. At typical press speeds, plate alignment can be unstable. The way it works is that some dots are big and some dots are small depending on their tonal value. The larger the dots, the more ink they pick up.

The most commonly used line screen dots are 150 to 300 dots per inch, depending on the screens used by the printing company. Printing companies pick one type of screen and use it for all of their printing, so you can’t ask your printer to use high-dot line screens. One problem is that conventional screens use a lot of ink which builds up. Details are reduced due to flooding the paper with too much ink. The color gamut is the range of colors that can be printed. Too much ink inhibits subtle colors and tones are lost because the color gamut is reduced. Subtle colors cannot be printed and moire patterns can appear in textures and patterns. Another problem is banding in color gradations because it is difficult to print smooth transitions of color tones with AM screens.

The other detection method is known as FM (frequency modulation) stochastic (stuh-kas-tic) screens. There are different brands and they all have their own unique proprietary variations. These types of screens are different because FM screens are made with small flecks similar to the grain of photographs. As an example, I’ll talk about Kodak Staccato brand displays, which I’m most familiar with.

FM screens use irregular specifications of 20 microns to print in color. 1 micron is equal to 0.000093701 of an inch or 1,000,000 to a yard. A 20-micron screen prints 1,270 specs per inch. These tiny, microscopic specks are ideal for printing high-definition detail in photographs, fine art, type, and consistent color gradations.

Stochastic displays offer many advantages over conventional displays. They enhance detail and definition, clean up reverse text prints. They enhance detail in shadows and highlights, as well as a wider color gamut so more colors can be printed with conventional line screens. FM screens eliminate unwanted screen angle moire, subject moire and rosettes. The result is a continuous tone photographic appearance with more color stability throughout the print run. When color and tonal instability occurs using stochastic displays and misregistration occurs, sharpness and quality are not affected. These are just some of the benefits of FM displays.

Like all print buyers, you want your advertising, sales, marketing and branding promotions to be impressive and attract a lot of attention at an affordable price. You may be surprised to learn that the cost and turnaround times with FM screening technology are probably no more and may be less money than what you’re paying for conventional AM screen printing.

The next time your color printing is ready, ask your printing company what line screens they use and if they use stochastic screens. Don’t be surprised if you’ve never heard of it. If they can’t, you can purchase a higher quality print by finding a company that uses high definition FM stochastic print screen technology. When excellence is available, good is not good enough