no offense intended but here's my shot at the "is it plugged in?" question: are you blocking the screen with a photosensitive emulsion?

Sounds like the exposure time isn't long enough

1000w bulb might be too much. try using coins or business card to do a test burn. That will at least give you and idea if the transparency is to thin. I have 40w florescent bulb and it take 2.5min to expose. I've also used 500w halogen at around 4 min exposure. It might be a 30sec to a 1 min exposure.

If you need to thinking up your transparency, print to and double them up when you expose.

I've actually had a couple of things like this happen to me. it sounds like you aren't exposing it long enough, and also diazo emulsion might require a certain kind of light (I think I read that somewhere). I use photocure txr emulsion, you don't have to mix it, it's actually pretty cheap, and the exposure time is usually less. also, sometimes if you put the emulsion on thicker the side of the screen clesest to the light exposes first, and the other side doesn't. when you wash the image out you actually wash ou the emulsion on the other side of the screen, and the emulsion wants to come off the other side. Most high wattage lights like that do have a coating on the glass to block uv light so that it isn't quite harmfull to your skin and eyes, so no matter how bright it is, the uv light might be blocked. do some research to see if that's the case.

Em, assuming that your emulsion is okay, i.e. fresh, mixed and stored correctly, I am positive that you are not getting enough UV light to your emulsion. The Quartz Halogen bulb produces very little UV spectral light and is mainly used as a work light. If yours has a glass covering the lamp itself, the glass is most likely coated with a UV inhibitor to keep the workers from getting sunburned! Remove the glass and you will get some UV light, but even then it will take anywhere from 6 to 12 minutes to expose diazo emulsion on a 110 mesh from about 24 inches.

Also, all bulbs weaken over time. If your bulb has weakened from use (it may be new to you, but still quite old) it may need to be replaced.

An important thing to remember that it is not the opaqueness of your film positive that you should be overly concerned with, but the clearness of the film through which the light must pass and harden the emulsion and the UV intensity of the lamp. The shorter the exposure time the less chance of the light passing through the opaque areas.

Speedball products are fine for hobbyists and students but are not used by professionals. The oldest emulsion company is Ulano, which was purchased a few years ago by the largest emulsion manufacturer, KIWO of Germany. Ulano products are sold in England by Coates Screen Supplies in Leicestershire (phone +44 0 1530 275020) www.coates.com. Coates stocks many professional lines of supplies. You can find other dealers at htttp://ulano.com or at kiwo.com online.

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Bill Hood
School of Screenprinting
schoolofscreenprinting.com