Have you ever received a screen from a screen exposure service – for example, like us at CPL Fabbrika – and needed to rectify some issues with the screen, like those small holes that let the ink through? How do you rectify such issues without having to expose the screen again from scratch?
The issues you often find on screenprinting screens are microholes which allow the ink to pass through where it shouldn’t.
It’s possible to close these holes quite easily by using a small brush to add a layer of screen printing emulsion.
The screen should then be exposed to light to harden the new layer of emulsion.
To do this you can use the same exposure unit used for initially exposing the frame or you can just leave it in sunlight for ten minutes.
You can also rectify the above-mentioned issues using a suitable Screen Catalyst, a thick water-based tempera. The only downside to this is that it won’t be possible to subsequently clean and reuse the screen, because the Screen Catalyst can’t be removed by strippers.
However, on the other hand, if the problem is related to excess product on the screen, it’s not possible to rectify this by scratching away the excess emulsion in order to open up some parts of the mesh with a view to changing the design.