That's actually a damn good question. SB38 can be found on the kitfox web page. Apparently I have been hallucinating because I just read through the entire thing and the material type isn't mentioned anywhere.

Possibly I've read what others did, or possibly it's because I happen to have some 0.016" stainless.

Astute readers will observe that the SB lists the Vixen but it is tribal knowledge that all model 5s and on need reinforcement.

The SB states that the kit with parts will be provided free of charge but it is a Skystar document and I don't feel like it's the McBean's responsibility to fill that order.

I made two paper doll iterations before arriving at what I think will be the ideal flat pattern.

Interested to hear what material others have used