Friday, 13 August 2010

A short lesson in screen printing.

You will learn, as time goes by, that I have a bit of a thing about screen printing - at some point I will endeavour to but a pile of pictures up of how I use this technique in my own work (when I have the chance), but I thought that since I had a few moments spare last week, I would get a couple of screens up and running ready to print at home this weekend. This is something that we try to do a lot of at college, so it won't hurt to put this post up on the blog so that the newbies can get some sort of an idea as to what it's all about. If you already know, then well, too bad!
The silk screen - basically a frame with a mesh fabric stretched over it which is then coated in a light sensitive emulsion (like a piece of phot paper), which can have images exposed on to it and then ink pulled through the resulting "gaps" which are formed to produce a permanently printed image on cloth (or paper) - confused? well give it time, things will become clear.........

The darker of these screens is the coated one, the other is just to show what the mesh looks like.

My images - all copied onto acetate so that only the light can travel through the ground but not the image - this will then allow the majority of the screen to become "hardened" in order to prevent the ink to travel through - only the images will provide a gateway through which the ink may travel - I'm confusing myself now.....





The exposing unit - basically a big black box with uv light bulbs in it - a vacuum pump keeps the lid nice and tight and the exposure begins, as you can see, you place the acetates facing right side up and the place the coated screens flat on top.



Set the timer to 4 minutes and away you go......

once the timer pings, you need to race the screen to a water supply and soak each side BEFORE you turn the lights on, we have a specially darkened wash down area for this - as if by magic the images appear, and if you hold the screen up to the light once you are done rinsing, you should be able to see right through the images.





Once exposed you need to tape up the screens - as you can see, there are gaps around the coated area and if these aren't protected the ink will seep through and ruin the cloth you are printing, to do this you need gum strip and a bowl of water - it is very important though to avoid getting the excess sticky water from the saturated tape onto the exposed images, as this will "block" the screen by causing a permanent gluey barrier.



Watch out for the next installment, coming soon ......

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