The images on my screens are not washing out correctly, why?

This question is taken from our FAQ’s. At Wicked Printing Stuff we pride ourselves on helping our customers. We don’t sell you stuff and leave you to it. We WANT to help you, whoever you are, from hobbiest to professional business. So please check out our buyers guide, FAQ’s, product sheets or ring us with any questions.

The images on my screens are not washing out correctly, why?

This can be for a number of reasons, here are a few things to watch out for:

  • That you are doing all parts of the emulsion and exposure process in a light safe environment with NO outside or bright light. This includes mixing your emulsion, coating your screens, drying screens, exposure, and washout.
  • That you are not coating your emulsion too thick. One coat both sides should do it, with a nice even spread. There are sometimes where you may need some extra coats e.g. printing transfers and printing white onto a dark garment but you will need to adjust the exposure time.
  • That your film positive is very opaque and dark. If you hold it up to a light and can see through it, you need to double print your film to achieve a more opaque image.
  • That there is positive contact between your screen mesh and your positive film. If the film is not pressed completely against your mesh then you will get light reflection between your positive and your screen which will result in a blurry and not clear image. That’s why the glass is so important.
  • That you are exposing your screen for the correct amount of time, which will depend on the exposure system you are using. If you are unclear on exposure times please feel free to ask us. The simple run of thumb is – if the emulsions washes off too easily and you start to lose the stencil then the screen is underexposed and if after prolonged washing the stencil does not come through they you are likely to have overexposed the screen.

via Wicked Printing Stuff, your home for screen printing equipment and supplies – FAQs.