Oh no Pinholes in my screen?
There are a few things to do, most of them are about keeping the environment clean. This can be a little tricky in some screen printing studios.
Make sure that your coating trough is clean. I have got into the habit of washing the coating trough prior to use.
When sensitising your emulsion make sure the powder is truly ‘well stirred in’.
Make sure you have degreased your screen before you coat with emulsion, if you leave screens around without sealing them it’s surprising how much dust there is. If you are going to use the screens immediately then seal them in a black bag.
Make sure the glass on your exposure unit is clean – dust gets every where! If you do find pinholes then you can either cover them up with tape or you use a screen filler which you can apply with a brush to cover the hole.
Make sure you use solvent resistant fillers with plastisol and solvent inks, use water resistant screen filler when using waterbased inks.