Thai Official Statistical Labels (Stamps)

I have this set of Thai Official Statistical Labels (Stamps).

Not sure if they are to be considered as Fiscal or Postal stamps, or maybe Semi-Postal.

How should I classify them?

Great scans!
I shall email Jos Sanders for you Hilik,
he is the "go to" fella for these.

Just hang in there.

Further Reading
http://goscf.com/t/71005 br /

Hi

These are test stamps. Here they are, in order by denomination.

Jim

I know what they are. I don't know how to classify them.
Read my question.

Hello Hilik,

These Thai, so called statistical stamps somehow appeared in the Thai postal catalogs.
There are for sure not postal. I think they were never used via post offices but on interdepartmental mail which was carried around by some government clerk.
Most of these stamps are existing mint but I have seen a few with cancellations, these cancellations were not postmarks but some government issued cancel.
I have no idea why these stamps have values printed on them ranging from 10 satang till 2 baht. That indicates that departments would have to pay to get those stamps and that certain values were used for certain weights(?).
It are also not revenue stamps, they were not used as receipts or proof of payments.
My best guess is what the stamps say. The top line on the stamps reads "test label" so I would classify them as cinderellas.
Since most of these stamps are available as mint, issued without gum, I think this was just an ill conceived government effort to do something. I never heard of any final report on the "statistical results" using those stamps in the government inter office mail.

Hi Jos,
surprised they are not mentioned in Blakeney's Catalogue
even under the Cinderella section.

Are these test stamps in the same category as poached eggs? Printed for training purposes?

Opinion.
I don't think so,
The Thai (intent) cynosure was Statistics on mail movements,
not training staff.
Open to correction.

Both quite at home under the broad umbrella of "Cinderellas" though
if that is what you meant.

Here is a stamped 20s one.
Not researched.

Seems it was issued by the Post & Telegraph Department..

Pmk : Nakon Ratchasima perhaps.

Hilik,

your letter from the postal department is very interesting. I am asking around in Thailand if anybody has detailed info on these "statistical" stamps.
I had quite a large selection of them, Thet were printed with wrong values, wrong frames etc. Plus unlimited shifts between the colors on the bicolored stamps. They were extremely poorly printed, and I am surprised to read they were letterpress printed. Letter press is supposed to be superior quality printing. Thai letterpress printed stamps by companies like De La Rue in England between 1946-1950 are some of the best printed revenues I have ever seen.