Sc#1700 Flag Over Inukshuk - Fluorescent Paper

I have just recently finished inspecting about 5500 used copies of this issue and was trying to separate them into the 2 cataloged types (F back and NF back). However, I soon realized that I could easily find 3 distinct levels of fluorescence on the back of the stamps (NF, DF, F). When I turned them over to inspect the printed side, I again could easily separate them into these 3 levels. In fact the breakdown is NF 18%, DF 73% and F 9%. Since the Unitrade catalog didn't mention any different fluorescent levels for the printed side of the stamps, I had never checked the mint booklets. When I did, the 3 different fluorescent levels are very obvious.BK236/237 are DF, BK237A is F and BK237C is NF as shown in the photo (sorry about the quality...). Has anyone else noticed this? Also, I do not have BK236A, BK236B or BK237B so do not know where they fall into this. If anyone has these booklet and a UV lamp, I would appreciate feedback.
Cheers

Is DF a separate variety? I always assumed when determining the back fluorescence on this stamp, it either fluoresced (F) or didn't (NF). Never thought to try determining fluorescent intensities (but then, my census of this issue is WAY BELOW 5500). Thanks for the analysis anyway--I'll have to look at these guys again.

Regards, Robert

FGM,
Great work on this study. You should consider a membership in the Elizabethan II Study Group. This is the kind of study that is relevant to modern Canadian stamps.

I agree that there is a distinction between F, DF and NF. In fact many stamps in the Unitrade catalog are listed with all three papers.

You might also consider sending an e-mail to Robin Harris (editor of Unitrade Specialized Catalog of Canadian Stamps). He also manages and edits the Study Group/website.

http://www.adminware.ca/esg/index.htm