USA Sc#15 Or 33, But The Color Is Wrong...

Hi all,
I have what appears to be a Scott 15 or 33, but the color is a bright blue.
Any help on identification is appreciated.

Cheers!

Mick

This is a color changeling, it previously was a green stamp. It is damaged by exposure to environmental and/or sunlight. You can learn more here
http://stampsmarter.com/learning/Ar...gelings.html
Don

Thanks Don!

appears to be a #35

Right.... #35. It's only been like a week or so since the last green stamp turned blue thread.

Agreed that it is #35, type V. It can't be #15, which is imperf. We need to go through all the possible stamps with the same basic design before deciding which it is. And type V is illustrated with descriptive text below it.

Not sure what was used when this stamp was printed but in the 1920's and 1930's Phthalocyanine Blue BN which is a synthetic blue pigment was introduced to dyes and inks. Blue even in the 1800's seemed to be the strongest of the pigments.


From wikipedia.

Phthalocyanine Blue BN, also called by many names (EINECS 205-685-1), is a bright, crystalline, synthetic blue pigment from the group of phthalocyanine dyes. Its brilliant blue is frequently used in paints and dyes. It is highly valued for its superior properties such as light fastness, tinting strength, covering power and resistance to the effects of alkalis and acids. It has the appearance of a blue powder, insoluble in most solvents including water.