1. Sanja Mahovic Poljacek, University of Zagreb Faculty of Graphic Arts, Croatia
2. Tamara Tomasegovic, 1University of Zagreb Faculty of Graphic Arts, Croatia
3. Gordan Vugrek, University of Zagreb Faculty of Graphic Arts, Croatia
Screen printing is a reproduction technique used in wide application ranges; from artistic reproduction to industrial sector. It can be used for transferring of the printing inks on different substrates and for transferring different technical coatings. It is a process in which the printing ink is transferred through a screen printing stencil (printing plate) on the printing substrate. The quality of reproduced image depends on number of factors, i.e. the fineness of the screen, the diameter of the screen threads; type of weaving, mesh openings and the percentage of open area between weaved threads. Nevertheless, considering the fact that printing stencil should be made by exposure of emulsion layer applied on the screen mesh, the colour of the mash has the significant influence on the quality of reproduction of very detailed images.
In this paper the quality of reproduced images has been evaluated by modification of exposure times of emulsion layer and by changing the colour of the mash. The white and the yellow mash have been used. Other parameters in the printing plate production process have been constant. The quality of reproduced images has been evaluated by measuring of surface coverage of defined fields on the printing plate as well as by measuring the dimensions of image elements. Microscopic evaluation has been made as well.
The results have shown the influence of the mesh colour and different exposure times on deformations of image elements. These results can be used for defining the recommendation parameters in the printing plate procedure for reproduction of fine illustrations and images.
Grafičke tehnologije i dizajn