Scott 711 Undocumented Color

Hi all,

Just curious if anyone has any idea what could have caused the color on the 711 to be brown. Overexposure to light? Chemical reaction to some solvent? Issue during production? It is MNH and gum looks like original to me (though I am no expert). Scott catalog only lists red orange. There are only traces of the red orange. The normal stamp is on the right for easy comparison. Thanks all.

Lou

Looks very much like oxidation to me.


Peter

Thanks Peter. Seems you are right. I searched for stamp oxidation and found this in another post:

"Oxidized - a term that is often used to refer to stamps, especially stamps with orange hues, that have darkened with age or from contact with air or sunlight. It is often assumed that oxygen is the culprit. In most cases it is actually the sulfur in the air, albeit in minute quantities, that combines with the metallic component, often lead, in the colored pigment. Nearly all metallic sulfides are black and this is what "darkens" the stamp. The sulphurization is reversible with the application of hydrogen peroxide, which replaces an oxygen atom with the offending sulfur atom, restoring the color."

It's not an expensive stamp and it is a duplicate so I think I will try the peroxide experiment and see what happens.

Lou

Lou, let us know and see what happened with that stamp!


Peter

It actually worked. Stamp is restored.

I took a Q-tip dabbed with peroxide and carefully painted the front of the stamp with it. I could see it start to change color as the oxygen atoms replaced the sulfur atoms. I gave it two coats of peroxide. After it dried the gum was untouched and it looks perfectly fine.

I never expected to learn about chemistry by collecting stamps!

Lou