Someone already mentioned this before, but at 
least for the AIC series, almost none of the 
backgrounds match.  I didn't notice this until I 
purchased a cel a while ago from you that I 
thought had a matching BG.  After watching the 
DVD, then I found out it wasn't matching.  If 
you're not sure, it wouldn't hurt to mention 
something like "background may not match".  
Thanks.