Im making a couple of backglasses this weekend... below is the method which ill outline in stages.
Obviously, first thing we need is a sheet of glass.. make sure it gets tempered and edges are smoothed. 4mm is normally thick enough for any backglass.. some early EM may require 5mm. If you go under 4mm for tempered then you risk warping in the oven as the glass is annealed.
Once you have your artwork ( a file should be in the region of 20Mb plus to get good results) you need to have it DOUBLE struck with ink and printed in REVERSE. If you go single strike on the ink, the colours wash out when its backlit. Its printed in reverse so the print sits behind the glass and gives the illusion of a screen printed version.
STEP 1.
Lay glass down... spray lightly with water and a couple of drops of detergent and wipe off with a SOFT vinyl applicator... this removes any tiny particles.
Then respray lightly with your water mix.
Place the print backing paper side up onto the wet glass.. the print will stick slightly due to the surface tension in the water layer... this allows you to peel the backing off spraying as you go.
Once backing is completely removed you can lift it up and flip it over onto the glass. The water/ detergent mixture allows you to move it around to align all edges correctly
You can do this dry which is quicker, but your alignment has to be exact to start with.. i only do it this way if i have another person helping.
Once in place, a light spray again to allow the applicator to move across the print smoothly. Its essential that a soft applicator is used.. we are wiping on the printed ink here and it scratches very very easily.
To get the water layer out.. hold print down with one finger to start and begin at the bottom ( edge nearest you), place applicator in the centre and wipe towards one edge... move back to your centre and wipe to other edge.
This now has your print held in place and going from centre out, you can gradually move up the glass making sure your overlapping yourself each time.
Once this is done we need to put to one side to dry off a bit... when done wet the edges like to curl up and so you have to go back several times and reapply these. This is the downside of the wet method... had i done it dry i could have gone to the next stage straight away. Both methods have their downside.. wet takes longer, but dry risks misregistration and also bubbles which stand out like ripe plums on a bulldog.....Pinball machines make great resting surfaces!
Part 2 next....