Someone in my office recently asked me if I could have two mezuzot checked for her. The one on the left is what the owner of her apartment left on her front door. The one on the right came from her grandmother.
Both of these mezuzot are really small (5-6 cm). They seem almost too small to be kosher - meaning that any slight deviation in the height of the letters makes it look questionable. Is there any rule of thumb about the minimum size of the klaf?
(The one on the left is definitely passul - it has cracks in the klaf that run through the letters. The only thing strange about the one on the right is that it was rolled vertically instead of horizontally.)