There are two different screen printing methods: the flat bed method and the rotation method, of which the former is most common for printing graphic paperboard. Screen printing is particularly suitable for substrates that are too stiff to be printed in other presses. Some screen presses are also capable of printing much larger sheets than normal presses. These factors make screen printing ideal for producing large paperboard displays.
Paperboard has some clear advantages in screen printing. A substrate with low amounts of dust and debris is important in all printing methods, but in screen printing it will have more direct effects on the production economy and perhaps also indirect effects in print quality. Spots in the printed image from loose fibres will eventually force the press to be stopped for cleaning. As a result production time will be lost and the mesh may also be clogged with partly dried ink, distorting the hues and image details.
The smooth coating is also a highly important advantage, since it will not absorb much excessive ink. Screen inks are expensive and screen printing produces a much thicker ink layer. This, of course, makes it more resistant to scratches after a good drying period. Also the ink layer retains its hue and/or saturation better when exposed to sunlight, compared to other printing methods. Ink jet in large format is gradually moving in to replace screen printing for certain applications.
The principle of flatbed screen printing.