Netherlands Fluorescence Variations

I am sorting through my 1953-67 Juliana definitives to identify the fluorescent stamps as identified by my NVVP catalogue. Apparently there are 12 issues from this set having the aforementioned characteristics. In using my UV light, I see three differences. Obviously one is regular paper (no Fl) but there seem to be two other paper types. One shows up as a bright white paper and the other with a definite yellow colour under the light. Is the yellow one the fluorescent stamp?

DeeBee, the one in the middle is a booklet stamp. It would be listed in a different section of the NVPH catalog. If you have any other question after reading the booklet section please do not hesitate and come back to this post


Peter

The left one, as you write is ordinary paper (NVPH 621)
The imperforate right side identifies it as a booklet stamp (NVPH 621K).
Both exist on phosphorescent paper. The phosphorescence show a yellow reaction.
The third is a sheet stamp on phosphorescent paper (NVPH 621b).

The paper of the booklet stamp is whiter under uv-light, but soaking in water with some fluorescent agent can cause a fluorescent reaction.

I have made better pictures.

This shows luminescence. The image does not do justice to the bright white luminescence of the bottom left stamp (your central stamp).



Turn off the light and you see the bottom left stamp does not have phosphorescence.

Please note: ordinary vs. phosphorescent paper, not ordinary vs. fluorescent paper is what differentiates these in the NVPH catalogue.

My 2015 'Speciale Catalogus' lists booklet variations with an imperforate stamp directly after the main listing. Each section is followed by a section for the phosphorescent papers.
I am not sure when they introduced this, as I think I remember the older catalogues did not list these booklet stamps in the main section.

Thanks for all the great replies. Yes, I am aware that the middle stamp in my photo is a booklet stamp. I'm sorting through those ones as I put together an album page for booklet singles in my Davo album - it just happened to shine brightly under my UV lamp. I was just wondering about the fluorescent differences. It seems that I need to sort out the ones that are phosphorescent rather than fluorescent. Just have to wait until dark now. The stamps listed in the NVVP catalogue 618b - 634b are phosphorescent. Are there catalogue numbers for the fluorescent stamps?

Not in the NVPH 'Speciale Catalogus' that I am aware. I do not think it is intentional fluorescence.

The 12 cent stamp exists on fluorescent paper called 'Gouda' paper (1962, NVPH 776). This was a trial with an automated optical letter facer in Gouda. The fluorescence is yellow as well.

Yes, I have that one. It was printed on unwatermarked paper. There are a couple of others from the numeral issues on that same paper and unwatermarked - not cheap, either.