Screen Printing Forum

Hi I'm new to this and I have a question

After exposing the light to the emulsion . And I wash the screen it is extremely difficult to clean the silk which has the image burnt on to it

It comes out yellow first then starts to show the image and the emuksion does slowly dissapeaer although bot completely could I be over exposing the screen ??


Thanks

Sounds like you have overexposed the screen. But here is a link to a exposure test it shows you step by step on how to do it.
http://www.positivityltd.co.uk/Tutorial ... ation.html
The only true way to figure out your exposure time is to do an exposure test it is easy and will give you the numbers you are looking for.
Also make sure your emulsion (I'm assuming you are using direct emulsion) is mixed correctly if you have to add Diazo and that it is not out dated. Also make sure you are drying your screens in a dark room after coating and you are not getting them over 100F. Any of the for mentioned items will cause your emulsion to start to expose and will ruin your image.
Hope this helps

Could be your positives burning through, try putting a coin on the next screen, if it washes out before your positive it suggests burn through, if they are both slow it suggests that the emulsion has gone off.