I had the same problem once. I just used a Q-tip 
moistened with a little alcohol and gently wiped 
over the prints. Even though such trace amount 
evaporate quickly, I used the other tip moisted 
with water to removed the alcohol. Then just dab 
it dry with a soft lint-free cloth. My prints 
were fresh though, probably when the seller put 
it in the bag. 

p.s.- SHOW HER!! SHOW HER!!  ^_^