Modern -- limited to Topps Base and Topps Gypsy Queen for me -- have to be in near mint shape. Period
Vintage, which is most of my buying and the limited trading I do, in order from worst to me to least important to me:
Trimmed - I won't buy. Period.
writing / glue / tape / pinholes (adding paper loss here) - pretty bad, for super vintage (like pre-1930, I'll consider writing on the back or a pinhole, or paper loss if I don't lose stats), but I usually won't take these
creases - really try to avoid actual creases, but accept them for pre-1930 or so. Wrinkles are ok.
soft corners 1,2,3, all 4 -- I try to avoid them, but it's not prohibitive, even in mid-60s cards.
centering -- don't care that much, but I try to avoid miscut. As long as the picture's there, centering isn't a big deal.
bend or curve due to card storage -- could not care less; it's going into a binder or holder, where it will appear straight.
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