[almostdone]

I have read many theories and experiences with soaking a card but have not tried it myself. One thing that hasn't been clear to me is what time frame cards are ok? I know T cards seem fine and modern are not but approx when is the cutoff? Only prewar? What about Goudey or PlayBall? Bowman, Leaf or early Topps? Just looking for clarification before I try anything.
Thanks in advance,
Drew