Sigma Screen Printing Chemicals

A screen is made of a mesh stretched over a frame. A stencil is formed by blocking off parts of the screen in the negative image of the design to be printed; that is, the open spaces are where the ink will appear on the substrate. Before printing occurs, the screen must undergo the pre-press process, in which an emulsion is scooped across the mesh and the 'exposure unit' burns away the unnecessary emulsion leaving behind a clean area in the mesh. The screen is placed atop a substrate. Ink is placed on top of the screen, and a squeegee is used to push the ink through the holes in the mesh.