T206 Wet Sheet Transfer vs. Impression Cylinder Transfer

[Sean]

A couple BST threads discussed WST and Cylinder Transfers, so I hope that this thread can help.

A WST is usually caused by a printer placing a sheet of cards which are not quite dry on top of another sheet. A faint amount of ink transfers to the other sheet. WSTs are usually very faint and lacking in clarity.

ICTs are quite different. Quoting Ron Kornacki," ... offset printing (is) where a plate image transfers to a blanket cylinder and then onto the paper. If the paper is not fed, the blanket image will transfer to the impression cylinder. If that happens, a reversed image would print on the back side of the paper the same time the image is printed on the front. Normally the impression cylinder would be cleaned if a misfeed happened before feeding another sheet in to avoid the error reverse printing." If the cylinder isn't cleared, you get an Impression Cylinder Transfer.

The ICT images are reversed, just like the WSTs. However, the ICT is much darker and more clear, as it didn't transfer from a different sheet, but was printed directly on the back of the sheet being printed.


For comparison, here is a WST (Bescher) followed by an ICT (Bowerman):


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[Sean]

As a further example, a couple WSTs (Ganley and Rucker) followed by an ICT (Tinker):


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[Jantz]

There are two types of Wet Sheet Transfers.

Those that happen during production in factory (Rucker) and those that happen outside the factory after production (Ganley).

[Sean]

Jantz, how can you tell which happened in the factory from those that occured later?

[z28jd]

The Ganley was from a storage issue. There are quite a few Sweet Caporal cards out there that have the fuzzy image transfer, like either from the cards getting wet, or being stored in a damp place. I actually have two(and have seen others) that also have the top right darkening with the same fuzzy image, so it may have been a huge stack that suffered some type of fire damage or storage issue.

Side-by-side you can easily tell the difference between a wet sheet transfer SC back and one that was moisture related after it left the factory, just from the crispness in the transfer

[steve B]

The post factory transfers aren't from simply being damp. I'm not sure exactly how they happened, but I did try to cause one using a soaked card and pressure over a few days. That caused no transfer at all.

There's a number of types of post factory transfers too.

I believe the Ganley was part of the dealer inventory that was in a fire years ago. I have a couple EPDG cards that are scorched the same way but slightly worse and when I wondered about why so many of the ones I saw had the same scorching someone mentioned the fire. So maybe heat plus water plus maybe a chemical extinguisher?

The Bescher I believe is also post- factory. Unless they were using a multi color press, it would be very unusual to get that many colors involved in a wst. Cards like this I suspect the transfer is from years of abrasion caused by a bit of vibration.

The inks used are not water soluble, the carrier would have been either oil based or possibly something like Shellac or linseed oil. We'll probably never know for sure since the ink formulations were trade secrets.

I've shown this before, and while it's not printed by lithography it's a similar thing. A stamp printed on cardstock that left a transfer on another while in the mail. The last printing of these was around 1894, so the transfer came somewhat over 100 years after printing!
Similar cardstock, and similar ink is used in engraving.


What's really interesting about the cylinder transfers is that they show for sure that the press used for that card was a fairly modern press, possibly entirely rotary, and using plates. Some of the flatbed presses which used stones didn't have an impression cylinder and printed directly from the stone.The Willetts cards with the blue nail or wire mark have an impression of the object on the back which is a clear indicator of having been printed on one of those direct presses.

So there's solid proof that two different types of press were used.

Steve B