How to expose imagepac and xtra sachets in Stampmaker

You can expose imagepac and imagepac xtra sachets in a Stampmaker in the same way you do in an imagebox. It will in fact be much faster as the lights are nearer to the polymer.

There are two things you need to ensure: that the sachet is compressed flat and that the area in clamp around the negative is blacked-off. Then it’s just a matter of getting the times right.

1. Flat & level
Stampmaker clamps are set to be level at 1.9mm. imagepac xtra is set to 2.3mm or 2.55mm, imagepac is 2.55mm and 3.2mm. This means that you will have to either get a purpose made clamp from us or deepen the Stampmaker clamp by building up the edges. You can do this with tape or strips of plastic and card laid on top of the magnetic edge strips. The imagepac plus a negative should compress with a negative so that the edges flatten out under pressure. If the clamp no longer compresses tightly because of a loss of magnetism then you can simply tape the two clamp plates tightly closed. If the imagepac has creases in it then the cavity is too large. If the clamp lid rocks back and forth then the cavity is too small.

2. Black off around negative
Stampmaker has the advantage of being very fast, but the light that is reflected around the edges of the clamp will be a problem if allowed to enter the inside of the clamp. So black off the entire area of the bottom of the clamp, you can do this by laying strips of card around the negative.

3. Correct exposure times
Exposure times vary with bulb life and heat. Try to keep things as constant as possible by warming the bulbs up for 2 mins before each use.

Use 10 secs and 2 mins as a reference point.

For an A8 reduce the first time to about 5 secs.
For 3.2mm increase the first time by 5 secs and the second by 30 secs.
If text has filled in reduce second time to 1 min 30 secs.
Inkjet negatives stop more light than photographic and laser printed ones, so if you lose fine dots or lines wobble then increase the second time by 1 min.