Posted By:
Hal LewisBut my understanding is that you can only "stabilize" and "deacidify" PAPER products...
but NOT photographs!!

Accordingly, it is entirely possible that the photograph was removed from the cardboard and that the cardboard was dipped into the formula by itself.
Likewise, the photograph itself may have been emersed into some sort of agent (perhaps bleached with something like a copper chloride solution or a potassium permanganate solution) and then REDEVEVLOPED.
No, I didn't just make this all up.

ONCE AGAIN ... I am NOT saying that any of this is "wrong"...
I just wish that Mastro would have told everyone about the process and walked us through it.