Petert4522 contacted me to let me know he found a new variety of the BCA 5343 coil. He also offered to provide me with an example which I greatly appreciate. This will allow me to post this variety on the http://www.stampsmarter.com/feature...ng_Home.html
site in the US Tagging & Luminescence Database for which I am the Administrator.
Prior to posting on the DB, I wanted to do an analysis similar to the recent post I did on the BCA booklet of the same design. This new variety also has the "white/blue white" tagging as it is referred to versus the "green" tagging. The characteristics of the coils are similar to the booklets, but not exactly the same.
The first image is of the two coils under SW UV. The left has the green tagging and the right white. Under SW UV the tagging looks very similar to the BCA booklets.
This next image is of the two under LW UV, with the green on the left and white on the right. One thing to note is that the LW images tend to be appear much bluer than than they actually are when viewed. The white version is on a very hi-bright paper like the BCA white booklet. The coil with the green tagging when compared to the BCA green booklet is on paper that is noticeably brighter but not near as bright as the white coil.
This image shows the green tagging under SW UV magnified under an optical microscope. The taggant is fairly densely dispersed on the stamps surface.
The final image is of the white tagging under the same conditions of the image above. As can be seen the taggant is not nearly as dense, but is the same green color as the image above.
As with the BCA booklets the white appearance of the tagging is cause by the very hi-bright paper and less dense taggant on the coil.
This strip is also interesting in that it has a second tagging break. It has the typical tagging break that falls between the two stamps to the immediate left of the PNC stamp. The second break falls near the middle of the stamp immediately to the left of the PNC. Due to the irregular nature of the break I expect it was not intended but due to some other condition, possibly wear and would be considered a freak. This could be confirmed by looking at other rolls of white tagged coils.
Since the white version seems to be a consistent variety with a less densely tagged surface I surmise this is due to an intentional change in the manufacturing process. Again thanks to Peter for providing this example.