On the "Horror In Clay" Tshirt level it says to "add a note" in a "comment field" describing your tshirt size.
This, unfortunately, is wrong. It should read:
*** IF YOU ARE ADDING A SHIRT - You would add $20 to your current pledge and when we send out the survey at the end, let us know which size or sizes you want for your T-shirt(s). (NOTE: EDITED THIS- YOU DO NOT NEED TO COMMENT WITH YOUR SHIRT SIZE...THAT WILL BE HANDLED AT THE EXIT SURVEY.)
Mea culpa...sorry for the confusion!!!