Here is Bill Hunter’s recommendations on mylar. 1/2A gas 1/4 mil. (.00025). 1/2A and A gas 1/2 mil. (.0005). B-C-D gas 1 mil. Bob Hunter used 1/4 mil. on top of the Jap tissue on his Satellite 1300. Mylar on top of tissue has the added benefit of being fuel proof. Some prefer to put tissue on top of the mylar as they prefer the look of tissue. Weight of 1/4 mil. mylar is .8 gram per sq. ft.(clear). 1/2 mil. mylar is 1.6 gram per sq. ft. (clear) 1 mil. mylar is 3.2 gram per sq. ft. (clear). Jap tissue less dope weighs 1.5 gram per sq. ft. Tensile strenght of 1/4 mil. mylar is 6250 lb./sq.in. 1/2 mil. mylar is 12,500 lb./sq. in. 1 mil. is 25,000 lb./sq. in.