Sweden Gustaf SC #78 Gray Green 7ore Has Bluish Paper? Discoloration?

The very center stamp is the subject stamp! Sweden Gustaf Sc #78 Gray Green 7ore has bluish paper? Discoloration? Does anybody know?

I found pictures of this stamp on different websites, and it looks to me like the middle one looks more normal than the other two. The outside two look more or less discolored.


Peter

The stamp in the center is of nomal, fresh paper color.
The other two are faded (yellowed) with time (probably, exposed to sunlight).

i've added two more gustaf stamps outer two as to further the discussion! it seems no matter how many I find in my world collection sweden sc #78 .my (the) subject stamp seems to be different.

gentlemen.please send your pics regarding this stamp?

I've got to agree with previous comments that the middle stamp is the only "normal" one. The paper looks discoloured on the others and the colour has certainly washed a little. I'm not aware of any shades in this value. Do you have a good quality mint 7 ore stamp to compare them with? This would help to clear up some of the confusion.

TVOROG is correct something stain the paper ,maybe sun light ,water or even some cheap stock cards cause color to migrate on to the stamps .

nothing colors more than nicotine... and over the years I bet some old chaps have had a cigar or two in the room where they kept their stamps.

i'm disgusted with the smell of cigarets, but somehow the smell of old stamps that smell of nicotine and damp cellars is somewhat appealing :)

i might have some of those stamps in some left over collections, I only collect the classic ones, but I can look if you like?

the reason for a blueish tint couldn't be sunlight, the stamp would turn yellow on green..
on case of chemistry, plastic softener in stock albums, stamps blacken... oxidize.

could maybe find some more, but don't think it'll ever prove anything.

They look like typical toning (exposure to a humid, warm environment in proximity to an acid source like low grade paper, cardboard, or wood) to my eye.
Don

thank you guys.it looks as though the mystery has been solved..
i will post the same question in other forums <for personal use>..