"Okay --The cutting instructions say cut two 24 inch squares for the carrier (both pieces) and 1 four inch wide X 44 inch strip for carrier strap and loops. From heat resistant fab, cut one 21 inch square."
this is what amandasgramamma told me. mine was probably a bit smaller than 24 inches square, maybe 22.
here's pics of amandasgramama's -
http://www.quiltingboard.com/t-21943-1.htm
Featherweight here is the one who showed me one she'd made and i did it from what i remembered.