Help In Identifying Stamps Mexico - Mosquito Attacking Man

Hello,

please help in identifying stamps
I know that this stamps was produced in 1939, 1944 and 1947. Question for experts - what years of production of my stamps are in the photo?

Check the watermarks. Each has a different watermark.

"Brand?"

I think OP uses the term "brand" to refer to the stamp design + denomination combination. It could be the result of a language translation.

Serhii is a Slavic name. In Slav languages, a stamp is a 'marka', plural 'marky'. If you put a 'marka' through an online translator, it translates marka ==> (trade) mark ==> brand.

This is why, recently, our Ukrainian friend with his $ 100 album of rare stamps kept posting 'brands.' OP may also be using a translator.

NSK, that makes sense, except OP lists their location as the USA, and "marka/marky" is not the case in [i]all[/] Slavic languages, Czech and Slovak being at least two exceptions.

Slovakia is a strange country. For centuries, it was Northern Hungary. There are a lot of Hungarian words in that language. There, also, is a strong 'Saxon' influence.

Luckily, when you go to the post office and ask for "marky" you will receive stamps to put on your mail in both countries. Maybe, on my next visit, I should ask for "znamky"?

What people state as their residence and where they reside may differ, especially if they use VPN. But the USA and Canada also have quite a lot of immigrants from the eastern Slav countries. He would not be the first US or Canadian member here who has trouble with English. He uses both stamp and brand. So, it may be a language issue. Serhii makes me think of Ukraine.

NSK, yes! i'm Ukrainian. Now in USA with my family

Unfortunately, I had only one opportunity to visit Ukraine. I visited Kyiv and met with a friend. I had been planning on visiting Lviv and the southwest of the country. Hopefully, that opportunity will arise soon.

Sort your stamps into the three watermarks. In each of the years you mention, another watermark was used.

Yes.

Watermarks are very difficult to see

Lighter fluid can help

Good catch NSK

???
I don't know how to use this

Put the stamp face down in a small, preferably black, dish or other shallow container. Drip some lighter fuel - petrol, not gas! - on the back. It should make the watermark easier to see.