I am going to try something different, a small electric a control line stunt plane. What is a good lightweight covering material? Ultracote light? Others?

Dzl

The lightest covering I use is pvc. 75 gauge. It shrinks 40% and weighs 1/2 as much as the regular covering materials. It has no glue made on it so I use 3m77 sprayed on framework first. Heat with hair drier. regular heat gun will blow holes in it. At one time I found the stuff in a few colors, but all I seem to find now days is gold or clear. It's not quite a tough as the other covering materials, but it's good enough that I have used on many combat planes. I buy it on ebay. 100 gauge is too heavy, 50 gauge will be too light, so go with the 75. Dont confuse it with shrink wrap. it will be heat shrink pvc.
https://www.ebay.com/itm/40-x-300-Ft...kAAOSwak5ZxVxl