There is a program on Netflix called "Plane Restoration"It is a British show about various people restoring old WW1- WW11aircraft.From Tri-planes to Stearmans to Hurricanes etc. In the restoration process they describe the early covering materials such as cotton and linen , their limitations, and in restoring they go from these products directly to Oratex. They skip Stits Oratex may be pricey at acquisition but in the long run is the covering of their choice. I have not used it but appears very strong and forgiving My 2 cents worth of input
Carl