Interesting thread, I've been following this and will add some thoughts.
I've always felt the way Rob and Ted have, that sun exposure wouldn't remove all of the red in a card-and, I still pretty much feel that way. I may be wrong, but usually some cards missing red , where you can still see a touch of red (like that Cobb, for instance) can have another explanation.
As you can see in the corner of the Cobb, Chris is right- that corner shows it was tucked in a photo holder, commonly seen in old photo albums where you have one on the upper right, and one on the lower left.
So, I wonder about this- most pages in old photo albums are black. Could whatever they use to dye the pages black react to the red ink over time? That could explain why it did not affect the corner that was tucked, but the bottom of the top page laying flat on the card, over time, reacted with the red ink? Not sure, but something to think about?
The other cards on the montage- can't help but wonder about glue reaction (chemical reaction) on those cards....they all look heavily glued on....
Some people in the past have likened the sun exposure thing to a can that has sit in the sun, and over time the image faded......but, that's an image on aluminum or tin- the sun heats it up a lot hotter than the sun heating up paper? It seems like the sun would heat up a metal more than it would paper? So, I don't think that is conclusive (apples to oranges?).
I think it's possible that the red could dull a little over time due to prolonged sun exposure, but it's hard to imagine it would make the red completely disappear-I would think you would be able to clearly see some of the red still.
Keep in mind, these cards can be soaked and not lose any of the red. It's hard to imaging sun could remove it but water can't.
Again, I may be wrong. These are just my thoughts on this, and I am not a scientist. The Willis portrait is mostly found in red, but you also have many found in this burgundy type of color. Was this deliberate? The Abstein, mostly found in red, but many are found in orange-was this deliberate? Or, did that many Absteins get exposed to sunlight for too long? Sort of seems deliberate to me, because of how many examples have this color of orange. And, this Donie Bush card....look how red it is. Does anyone have an orange Donie Bush card? If so, are there any signs of glue residue on the back?
Sincerely, Clayton
|