I used the same preflash setup that I use for preflashing paper negatives, which is a type S-11 light bulb (120vac, 7.5 watts, standard base, frosted white round globe about the size of a table tennis ball, available in hardware stores) mounted inside a light-tight enclosure with a 3mm aperture, mounted 30 inches above the work surface in the darkroom. My typical preflash times for grade 2 paper negatives is about 8 seconds, whereas with the Harman DP FB paper I preflash for about 3.5 seconds.
Originally Posted by Kevin Kehler
I haven't tested the time delay effect with the Harman paper, but with grade 2 paper negatives I've not noticed any depreciation of the preflash effect over a period upwards of a week's time.
Jedidiah: This paper, like most, is sensitive mostly to UV and blue, meaning that it would take an extremely long exposure to do so using tungsten light in an enlarger. Plus, also keep in mind that its tonal range is actinic to orthochromatic, and the black-and-white renditions of your color slides would not show much exposure in the warmer tones like the reds.