Wednesday, 10 April 2013

Screen Exposure / Part 1 - Acetate printing...


If you've ever done any screen printing, you'll know that there are some magical moments throughout the process. The first is when your screen has exposed successfully and when you wash it off there's a sharp image and the detail is there that you had been expecting, without too many pin-holes or other holes in the emulsion to touch up.


The length of exposure varies depending on your exposure unit and the opacity of the image on the acetate (this is called the screen positive). Our exposure system uses two large overhead lights. The benefits of these are that we can expose very large screens, the downside is having to be careful to avoid getting a blurred image around the edges on the largest screens. We use very light spray of adhesive on the acetate to get around this. On a vacuum bed exposure unit the acetate is held tightly to the screen by air suction and this isn't necessary, but the maximum screen size is then limited by the unit size.

The process involves first putting your image onto acetate. Simplistically, you are making a black print onto acetate of every colour in your image that you wish to print.

Below shows a 1100mm wide acetate film being printed in the studio. Our printer prints a very opaque black and the acetate doesn't require any further treatment to increase its opacity.






















Here are some of the acetates for my design 'Night and Day' which I printed for an exhibition earlier this year...






















example of one of the background acetates...





















and the foreground...






















the finished print from these acetates, monochromatic in that instance.

No comments:

Post a Comment