Why Are Some Stamps Tagged And Not Others..?

Hi guys..Question why some stamps are tagged and not others..Look at this mini sheet of CAPEX 78 stamps...The 14 cent and 39cent are tagged and not the $1.25 stamp as shown below..

Also wonder why the 12 cent stamp was not added to the mini sheet..??

Robert

Robert, I thought about your first question for a second, and the answer came. Your 14 and 30 cent stamps were most likely for first class postcards and letters, all machinable. The $1.25 was some other, non-machinable rate. Since the taggant will damage the perforation pins someone decided the high value did not need tagging.
I have no idea about your second question.

Peter

Peter, you are correct about the "machinable" tagging. Even today, high value stamps are not tagged. It cost more to tag them, an extra plate is required.

No 12c was not put on the sheet because it was an expired rate, replaced by the 14c rate.

Well..Thanks guys..That answers my questions.
Robert

Thank you BeeSee, for your expertise. I think I read somewhere that the tagging damages the perforator pins, since it is a metallic ink. That is one of the reasons the Bureau of Engraving and Printing used the block tagging.

Peter

Peter, can you describe what block tagging is?

@Gilles:
Here is a brief overview on US tagged stamps. It has images of different tagging styles, including block tagging.
http://www.ebay.com/gds/Guide-to-US...58564/g.html

Gilles, back in the days that the Bureau of Engraving and Printing was the printer of all US stamps they figured that the tagging was damaging the perforator pins, since the taggant is metallic. It was decided to only tag the middle of the stamp, leaving all the edges untagged.
I am not good at taking UV pictures, but if you go to "search" you will find several posts that have excellent pictures.

Peter

Here is information on block tagging Gilles:

https://goscf.com/t/38111#38111