What is it?
Screen printing is a printing process which consists in passing ink through the very fine meshes of a screen using a doctor blade to be deposited on the support to be printed.
Screen printing is often considered a stencil technique.
The screen (made of a fabric stretched over an aluminum frame) is coated with a photosensitive emulsion (coating) which hardens when exposed to ultraviolet radiation (exposure) and clogs the fabric. The ink does not pass.
A film is positioned on the coated screen before exposure and allows to block ultraviolet rays at the places where it is desired that the ink can cross the mesh of the fabric. The UV-protected emulsion does not harden, it is removed with water.
The screen thus prepared for printing can be installed on the screen printing machine. The doctor blades and counter doctor blades are also installed and the ink is deposited on the screen fabric. The printing medium is introduced into the machine and kept in position during the printing process thanks to a suction table.
The ink is spread on the screen by means of a counter-doctor blade (coating), then the screen descends on the support to be printed until out of contact level. The pressure of the doctor blade allows the ink to be applied to the support through the mesh of the fabric in order to reveal the patterns.
After printing, the screen is raised, the support removed, washed and dried.
Advantages
Screen printing is a process that allows you to print many different and varied supports. In parallel, specific inks will be used depending on the type of support. One of the advantages of screen printing is that you can vary the ink deposit by using more or less fine screen meshes. This technique therefore allows a strong deposit of ink (5 to 10 times greater than other printing processes), which guarantees not only an intense color which lasts over time, but also good opacity.