SC 919 3 Cent Lantern - Odd Colour Under UV

I've tried but can not photograph the stamp while it is under UV and capture the odd colour explained below.

This purple faced stamp is flesh coloured under UV and the reverse is a much higher fluorescent than SC 919iv (Rolland paper with medium fluorescent back). Every other stamp I have is purple under UV.

The best example of the face of the stamp under UV is the flesh coloured SC 920 5 cent bucket stamp.


Here are camera photographs of the fronts and backs on a normal stamp (on the left) and the "odd' stamp (on the right in both photos).


The "odd" stamp's colouring is lighter than the "normal" purple stamp (on the left) as noticed in the left edge inscription and the Canada 3 across the top. Also, the lantern detail is not as dark.


The 'backs' photo does not indicate that either stamp has picked up a colour from the envelope it was mailed on.

Every camera and scanner and PC screen creates different colours/hues, but hopefully what I'm trying to portray is understandable.

Comments would be appreciated.

It is a used stamp and may have been altered by sunlight or something else environmental

Peter

Blackjag,
from your scan, the 5c appears to be a double or ghost printing, especially visible on Canada 5. May be it is only a result of a low dpi scan?

Peter - you are probably correct.

Gilles - you've confused me with the more experienced flyspecker - wert.
All images are from my camera. None have been scanned. I hadn't even noticed the ghost printing on the 5 cent so will have to relocate that stamp and check it. I just pulled it from a pile and threw it back after taking the photo.

Interesting BlackJag
Mine (920)has a few speckles of fluoro on the right white margin side (contamination ?), under UV. But I fail to understand your observation and did put the UV light on 917-922, the last 2 ones being tagged.

BlackJack,
What you have is a 919a.
I have noticed this exact same "feature".
It was printed by Canadian Bank note (CBN) and not Ashton Potter (AP) like 919, i,ii,iii,iv and v. All of the latter are perfed 14x13.3 while the 919a is perfed 13x13.3.
Check the perfs to confirm.

CBN uses it's own ink formulation that gives the stamp background color a pinkish hue under UV

Gilles - the 'ghost' was from a shaky hand holding the camera.

Renden - I was referring solely to the stamp's background changing from purple to pinkish under UV (as undertstood by FGM) and was not referring to the tagging.

FGM - I agree that it is a 919a, but no other 13.0x13.3 919a's change for a purplish colour under UV. I will attempt to photograph a normal 919a with the "odd" one tonight when it's dark enough. For whatever reason, I can not configure my camera's settings to capture the colour even though it is so obviously visible to the naked eye.

My thanks to everyone for their comments.

I have found the same issue, Canada sc 919a 3 cent lantern under an U.V light shows a flesh tone color. Is this an known defect or is it normal.