Distinguishing Scott 3980 From 3980A

Recently I was asked for an opinion on how to distinguish Scott 3980 from 3980a. Scott lists 3980 as overall tagged and 3980a as Prephosphored coated paper with surface tagging showing a solid appearance. I found the 3980a description confusing myself as both varieties are overall tagged.

The questions was whether the 3980 was the one that glows white or green. This question can also be confusing since neither glows "white" under SW UV assuming your UV source is properly filtered. With appropriate filtering, one appears bluish green under SW UV and the other a bright green/yellowish green under SW UV. Under LW UV one does appear whitish. Below are the two examples under SW UV.


The first impression some have is that the one that appears green under SW UV must be the overall tagged one since many overall tagged stamps appear this way. From the images above you can see both are tagged overall i.e. there is taggant covering the printed image.

The question is how to determine the difference. I examined the two under 100x magnification with a SW UV light source. Under magnification it is clear in my opinion which is 3980 and which is 3980a. Note images are somewhat blurry since the dept of field is so shallow and this also challenges a camera's auto focus.

Based on examining the diecut area under SW UV, 3980 is the bluish green example and 3980a is the green/yellowish green example. Under LW UV, 3980 is the one that glows "whitish". Hopefully people find this information helpful.

I appreciate the cleverness of your explanation, but I have to say I hope this is not how bizarre stamp identification has become. On the other hand, catalogue makers have been doing this right from the beginning. The earliest U.S. stamps were given different numbers based on the tiniest and least significant details, a tiny dot or an added line or slightly darker ink, mainly to increase the number of stamps collectors could look for. Some of those early numbers of supposedly different stamps have now been withdrawn since, it turns out, they weren't different stamps after all. At least these more modern stamps are differentiated by sub-numbers with "a" and "b" rather than entirely different catalogue numbers. That's a relief. Is there a "broken hat" variety, I wonder? Everyone is free to collect what they want, but I can't get into this level of detail and feel satisfied about it. If two stamps are identical but one glows slightly differently, I'm going to call them the same stamp. Nevertheless, I do admire the extent of your technical ability and your enthusiasm for this kind of detail.

Thanks for sharing this info.
I initially guessed that the bluish green tagging was 3980 rather than 3980a based on the fact that all of my 3980s exhibit this type of tagging. That I have been unable to locate 3980a, together with the fact that Scott gives no CV for 3980a, made me suspect that 3980a might be a bit scarce. So I have assumed that my 3980s ought to be the most common variety.

"The first impression some have is that the one that appears green under SW UV must be the overall tagged one since many overall tagged stamps appear this way. From the images above you can see both are tagged overall i.e. there is taggant covering the printed image."

Sorry, but I am going to have to strong;y disagree with you - what you have is not one 3980 and one 3980a, but rather two 3980.

You are correct in that both are Overall tagged. Difference is that green one I am convinced, is also on prephos coated paper. It gets its smooth green color from the prephos paper and the green haze from the overall taggant. Overall tagging alone is fairly splotchy under high magnification. Here are three types of AVR tagging. One is Solid (prephos coated paper), one is Solid (prephos coated paper) + Overall and one is Overall.

Anyone care to guess which is which.

My guess is that many AVR stamps printed in this timeframe were on prephos coated paper (Solid tagging)and so this is what they had on hand and used for some.

I examined a 3980a many years ago - too long ago to remember the details.

Back to correct the error of my ways. Based on discussions with other avid collectors and their conclusions I essentially forced a square peg in a round hole. I took eyeonwall's challenge to heart and continued to hunt for a prephos version of this stamp. After hunting down numerous sources/dealers I finally found one. While discussing an order I planned to make from Craig Selig, I asked him about 3980a. He indicated he had one used copy and kindly offered to loan it to me so I could capture an image and post for others. Below is the real deal.

Could you picture it next to a 3980 so people can see the difference?

I agree with eyeonwall ... a side-by-side comparison would be helpful. From your two scans, it appears to me that the tagging on 3980 is a bit grainier than that on the 3980a, presumably due to the use of prephosphored paper on the latter.

Here you go. The 3980 with bright green tagging can look fairly smooth, this coupled with the scarcity of the actual 3980a led folks, including myself to question its actual existence. I am happy that I can provide these images for others to learn from. Again thanks to eyeonwall for challenging me, that's how we learn.

The side by side comparison is very helpful and clearly shows the one on the right really is a 3980a.

" The 3980 with bright green tagging can look fairly smooth"

The smoothness or uneveness is not relevant. The only question is whether the taggant is on top of or under the ink. On your left wo stamps you can see a greenish haze on the inked areas proving it is overall tagged, while the right example the ink covers the tagging and there is no haze/the image is sharp, this tagging under the ink.

Embedded prephos is usually uneven, overall is usually smooth, but surface prephos varies widely from uneven to smooth and there are a number of issues that have surface prephos that comes both smooth and uneven (the most famous example is the 37c Flag coils 3632A from plates S3333 and S4444), so smooth or uneven can not be used to determne tagging types.

Your next mission is to locate a 4134a and show 4134/4134a comparison images (in a new thread so people can find it)

Not familiar with 4134a, how is it different from 4134?

4134 overall
4134a prephos