Pink Backs

Thought I would show one more recent buy. It is an example of a pink pack. It occurs on Scott numbers 425, 426 and the copper red shade of the 12 cent in the same series.

It is caused by the printing of certain colors using aniline inks. The color would bleed through the stamp and show up as a pinkish tint on the reverse. It also occurs on E11.

1847USA's glossary describes pink backs as:
Pinkback - a stamp whose ink has bled through the paper and is visible on the back as a pinkish hue. This resulted from the use of substandard inks made from synthetic pigments used in lieu of the normal inks imported from Germany when the inks became unavailable due to the First World War. "Pink backs" are found primarily on the two, three and twelve cent perf 10 single-line watermarked stamps, Scott's 425, 426 and 435a.

I'd link to it, but, well, you know...(thanks Amos). Speaking of which, the note in Scott is pretty similar to rohumpy's description, referencing aniline inks permeating the paper.

Bookmarking. Gosh So much to learn and so little time.

I have a few of those.. from that time period.. now I know for sure why they are what they are.

Stampvirgin, if you have a 2 cent pink back and want to part with it, name your price(within reason--they aren't that expensive) I have the 3 cent and the 12 cent and have been looking for the 2 cent.

I have a feeling that the identification of the 2 cent may not be so straight forward, since the color of the stamp is a carmine, or a shade thereof. The color of the printing shows through the paper somewhat and may mimic the pink back effect.

Anyway, let me know if you want to sell or trade. Thanks.

I believe I just found my very first pink back!

It's a perforated 10, single line watermark (190) from 1914 as seen on the front! WHAT A FIND!!
Specially to have a date on it and really decent centering

Would anyone else agree this is a pink back?

Well definitely a flat plate printing anyways! lol

At least I can't mistake that part.

I have a hoard of these 425's and this one and one other stick out like a soar thumb. They gotta be pink backs. You can see the difference Ten feet away.
Looking closer I think the ink spots are from another sheet of stamps after printing.
None of the lines match up to the frame of the stamp. If I'm making sence to anyone?

The ink marks are from the freshly printed sheets being stacked on one another and the ink from the bottem sheet got transferred to the back of the sheet stacked on it.

I agree, it sure looks like a pink back. It must be a Scott 425 for there to be a chance of being a pink back. If you put it next to others that you know to be SC 425, it should as you say stick out like a sore thumb.

I have two examples of Scott# 425 for comparison.

What do you think, Pinkback or not?

I would say left stamp, no, Right stamp yes