Blueprint paper comes in large sheets, and those sheets can be tempting to use without cutting. Sometimes you want to produce a much larger image than you can m ake with a camera or with a contact sheet. In cases such as this, a projector of some sort can come in very handy.

I’ve had good results with a tilt-head enlarger and a good halogen bulb, but few people have such a device. Most people, however, have access to either an overhead projector.

I’ve found that modern projector models with fresnel lenses are nice for experimentation, but the lens rings tend to show on the print. Also, the light is not evenly distributed. I suggest experimenting with fresnel replacements that will diffuse the light and evenly distribute it.

Also, try to find a projector with a head that lets you adjust the angle. A keystoned image may need adjustment.

Ben Millen has had good results with a 35mm slide projector. Check out his images here.

As with any exposure device, I highly suggest that you use a timer to control the exposure time. A darkroom timer is fine for short exposures, but for multi-min ute exposures, you will want something with more flexibility.