[Histonet] ? on frozen tissue artifacts

[histopath101 <@t> gmail.com]

I work in a reference lab and some of our frozen sections exhibit severe  
freeze artifact (ice crystals). The client claims it's something we're  
doing and we say they are not freezing them properly. We receive the  
specimens on dry ice and store them in a -20C freezer until we section them  
(no more than 1-2 days later). We never allow the tissues to thaw. My  
question: Can freeze artifact occur AFTER properly snap-freezing tissue or  
does this artifact ONLY occur during the initial preezing procedure?