Pink Back ??

Clark,
Thank you, thank you, thank you for the reference. I tend to agree with Larry Weiss that the use of the term "aniline dye" has been a bit too generic in the philatelic references I have been using. It's good to see that stated. And I positively agree with his last sentence. Not all aniline dye based inks behave the same, so the generic reference is only going to lead to the kind of confusion that started this thread in the first place. I know that I fell prey to it, since I knew nothing of the so-called "pink backs" but have seen aniline bleeding plenty of times with other material.


With Larry's comments in hand, what has been shown so far does raise doubt about whether or not other issues printed with aniline inks would show a "pink back" bleed pattern like those associated with these particular issues. The general testimony seems to be saying, "don't expect that." However, we have not asked whether a soaked "pink back" stamp would look about the same as earlier issues that show an aniline bleed after soaking. If you soak a "pink back" and the aniline ink runs as on the earlier issues, does the stamp then cease to be a "pink back"?

As I understood his first question, kc has a used stamp that showed an "aniline bleed" (my term) after soaking and wanted to know if it was a "pink back." Does that term go along with the appearance of certain mint stamps only, or does it belong to a class of stamps from that issue which were produced with a particular kind of ink that bled more readily than others? So far the consensus here is that the term "pink back" is reserved for a particular state of a particular set of issues known to have been printed with ink that tended to bleed more than usual in the production process.

Am I getting that right?

essayk,

Yes, apparently the ink or solvent used to print the "pink back" stamps bled into the paper behind the image. After reading the article, I am no longer convinced that the bleed was due to water or dampness. It may have been an excess of some solvent in the ink separating out from the ink emulsion that caused the reddish stain in the paper. I don't know of any reason to believe that it was water based.

I don't know if a pink back would bleed in water at all or in the same manner as the Scott 220 or early Bureau 2 cent stamps while being soaked.

Clark

"It should be noted that the perf 11 Special Delivery, Scott E11 "pink back" variety also exists."

Which I pictured earlier in this discussion.

I have both unused and used examples of the pink backs. The effect is quite noticeable. Being used or unused does not prevent recognizing the pink backs.

rohumpy would you be willing to show us examples of what you have as a full og mint and as a used? One of each, both sides?

"raise doubt about whether or not other issues printed with aniline inks would show a "pink back" bleed pattern like those associated with these particular issues"
the claret banknote postage dues used aniline inks and yet I have seen only one stamp which showed any bleeding. I suspect it was soaked with aniline based carmine stamps.

Has anyone checked the fluorescent properties of aniline based stamps? The claret postage dues glow orange under UV but I have a set which glows yellow-green.

Any ideas?