Struggling With The Difference Between 977 And 977i - Flourescence? :-/

Hi Folks,

So... way back in the mid to late 80s I used to collect stamps. I'd head down to the post office every month and pick up a corner plate block of the new stamps out that month.

Now, I have a collection of mnh plate blocks - all Canadian - all from 1984-88, and I'm going through them to see which, if any, I should consider selling separate from the rest. One I'll sell separate is the #929i Cradle - brown variety.
But then there's this one.. the 977 - I haven't the foggiest if it's the Non fluorescent (NF) or the Dull fluorescent (DF) - and shining my little uv light on them hasn't made me any more clear.

I was hoping that maybe someone out there might have some in their collection so I could see what the difference is. ?? or perhaps some sagely advice on if I should even care or not?
attached is the front and back of the stamps under UV - though, admittedly, poor pics from my phone.

Anyway, thanks for any advice you can offer

kind regards!
Stratus

Are you using a longwave or shortwave uv lamp in the photo?

The most definitive way to separate paper varieties is to have them together under UV light. (even then, sometimes...)
Or... find another issue with the same paper and compare it under the light. You'd need a Unitrade catalog to find one.
Welcome.
Paper variety is a difficult category in Canadian stamps, so... hang in there.

No1philatelist - I'm using a longwave - it shows the tagging almost blindingly :-)

sak - Thanks for that, I suspected it was a bit of a minefield - there are just so many that are worth more or less depending on the difference between DF and MF - On the whole... I think I'll probably stop caring since i'm just going to sell them. I'll just put them up on ebay and maybe someone who knows what they're looking for will get lucky and get a treat :-)

Thanks folks :-)
Stratus

Hi, and thank you for posting the question. Hopefully I can help with this...

I have attached a picture of the two different stamps - the partial left one is the NF version, while the partial right one is the dull version (the original picture size was 5.5MB, but this website doesn't allow large sizes to be uploaded, so hopefully you will still be able to see the paper differences...). I normally use a longwave UV Raytech LS-4 lamp for fluorescence (brightness) work on Canadian stamps as it provides the best differentiation of the paper brightness as well as that of the paper matrix (120V power). I have found that most of the small, battery-powered lamps are not able to distinguish well between the papers. The only exception is one that I bought a number of years ago from Unitrade Associates in Toronto, Ontario, which does a reasonable job (more recent purchases fail on this requirement). The problem stems from the wavelengths actually used by the various lamps, which are apparently not the same and thus reflect the paper brightness differently (they seem to have a different range of sensitivity to the stamp papers).

The NF version shows only a very few, brighter, fibers in the paper matrix, while the dull one has many more, though they are shorter in length. Overall, the papers fall into the NF and Dull (or DF) categories.

All that said, if the direct approach to determining paper fluorescence doesn't work, then try the 'relative' approach. The Unitrade Catalogue of Specialized Canadian Stamps includes a reference table as part of the Introduction section for determining fluorescence based on the different suppliers of the paper over the years (as best as can be determined). Please note that the original (oldest) listings of paper fluorescence in the catalogue DO NOT agree with the more modern ratings, and have been left in the catalogue as historical types (the overall scale of NF to HB from the early 1960s does not match the current one) . For this $2.00 stamp, the current edition of the catalogue doesn't provide good examples to go by (we need to be sure that only one fluorescence level exists for the particular stamp - in the past there have been many more listed, but over the years multiple brightness versions have surfaced so the listings have had to be deleted).

So let's just find a suitable NF stamp in the catalogue to see if the copy you have fits the same brightness level. A good example for this is Unitrade / Scott #864, when viewed from the gummed side. #977 NF and this stamp appear to be identical from the back (using both lamps I mentioned earlier). So if your copy of #977 looks brighter, then it has to be the more common, dull, version. The reason why #864 is a safe example to use, is that it has only been found with the NF paper fluorescence level.

I hope this helps - it is not simple to do this on certain Canadian stamps!

M. Zatka

Stratus said


Probably the best way to go as the fluorescence of the paper is just an uncontrolled part of the paper making process and nothing at all to do with the stamp printing. The only exception is "hibrite" paper which was deliberately made with a very high fluorescence.

AQ

Beware when buying long-wave uv lamps. The cheap ones use leds and are 395nm while "the good old fashioned ones" are 365nm which is the wavlength to go (at least for USA stamps).
Those handheld thingies are good for yes/no, but no more.
If you don't trust anyone, build them on your own like me:



At left bottom, a 254nm 8W lamp with glass filter, above a 365nm 8W lamp. Ventilation required as these lamps really are 8W (unlike the many/most/all? lamps that are advertised as "8W uv lamp") and seconds after switching on, ozone smell starts filling the room.