I got my new trays yesterday, but I was in a hurry to get to the P.O. and didnt stay to look at them, or ask any questions....

I just started tray 9 of 10 for my uppers, and 16 for my lowers. Im pretty excited!

I noticed last night that my #9 trays are SUPER clear, not foggy at all like they normally are, and they are slightly more rigid. Is there a reason for this? I thought maybe it was because Im almost done with my uppers, but my #10 trays are just normal.

Also, what kind of retainers did you get with yours? I was told to just use my last tray as a retainer until I get done with my lowers too.