Question About Tagging

First, what is tagging? From what I recall reading, it is an additive to the stamp itself to help with the automated sorting system? Is this correct?

Secondly, I saw in the Scott catalog that on some stamps it says tagging omitted and has a larger dollar value assigned. I have a lot of sheets and partial sheets from the 70's and 80's. Is there an easy way to identify if a stamp is tagged? A black light maybe? And what do I look for? I would hate to sell a sheet for below face value if it could be worth a lot more.

Thank you,
Robert

Hi,
There is a glossary of terms at left of every page which defines tagging
https://www.stampcommunity.org/dict...stamps_t.asp

And if you search this forum for tagging you should be able to get the answers to your other questions.

Don

I would not recommend the use of a "black light" to detect tagging. Instead, use a short wave UV lamp for US stamps. But be forewarned, many European countries use long wave UV rather than short wave. Many UV lamps have a selector mechanism to allow viewing of either short or long wave UV.

This is an example of what you see with stamp with tagging.
It usually has a greenish glow.

Earlier US airmails will glow orange.

Thanks for the replies everyone. Lots of good info on this site.

Where would the best place be to get a UV lamp? I assume it would be a specialty store of some type? Or can I get one at Wal-Mart?
Thanks again,
Robert

The best place is a stamp supply place like Subway, Amos Advantage, etc. The less expensive ones are not very powerful.

For example:

http://www.subwaystamp.com/PORTABLE...o/ZLHLAMT85/

Fantastic! Thanks! I do have a local stamp and coin place near me so I will check there first and if not I will be ordering one today.
Thanks again,
Robert

I am sure they can get one for you.