But with large printing areas, stencil thickness only affects edge definition. Tension in the mesh provides the hidden energy of the process. A screen should be tensioned within the range recommended by the mesh manufacturer. As the tension is increased, snap off can be reduced. Reducing the snap off also reduces stretching of the image and improves image quality.
Tension gives stability to the image.
However, too much tension can make the screen more fragile and can take the mesh close to or past its elastic limit, resulting in irrecoverable tension loss. It is vital that the frame be robust enough to resist distorting under the forces of the tensioned mesh, or the printing process will suffer. Also be aware that temperature has a considerable effect on mesh tension. Screens need to have time to stabilize when brought from an environment with a different ambient temperature. Floodbar The purpose of the floodbar is to charge the mesh openings with ink before the ink is displaced by the action of the squeegee.