Here is why my UV print exposures were so erratic...

For the longest time I could never figure out why my kallitype exposures were so erratic from print to print. Sometimes too dark... sometimes too light. I came up with every possible explanation under the sun, but tonight I finally figured it out...the real reason.

What I was doing was allow the mercury vapor UV lamp to fully warm for 5+ minutes while covering up the print in the vacuum frame with heavy stock cotton paper. Well it turns out that the paper I was covering it with is not UV opaque! It was getting significant exposure before the exposure.

So I finally figured it out quite by accident and thought I would share. Fortunately, now I have a working integrator so I won't have to warm up the lamp and time my exposures.
Received on Fri Jan 23 23:07:19 2004