Exposure Simulator

Stencils can be under-exposed, over-exposed or properly exposed


Under-exposure means that not enough light has reached the screen. This results in:

  • thin stencils
  • fine detail washing out
  • pinholes
  • delamination of the stencil during printing
  • breakdowns on the press
  • makes the screen harder to reclaim

When exposing your screen, the light is working its way through the emulsion layer from the back (the side facing the light) through to the top side of the screen (squeegee side). This is why under-exposed screens are sticky or give off unexposed emulsion scum/slime when rubbed/blotted on the top side of the screen. It is imperative that you continue washing out the entire area of the stencil even after your full image appears on the screen; if you don’t properly wash out your image, the last bits of unexposed emulsion will dry on the top of the screen and re-wet to fill in your stencil as you begin to print.


Over-exposure means that too much light has reached the screen. This results in:

  • light undercutting the edges of the film
  • fine detail washing out
  • difficulty washing out the image

A proper exposure holds the image details and lasts for the entire print run. The stencil is strong, with proper thickness and no pinholes. Fine lines, text, and shaded regions are properly defined.

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