CrateCruncher, I've built a number of Dirty Birdy kits, although they were the "original" Bridi ones, but many of them were done with fully sheeted wings. As long as you "pick" you sheeting correctly the weight is neglegible (although I always weighed all my sheeting on a gram scale) and that includes .75 glass cloth covering with paint. All the planes were used for event flying and all were very good for their time (although I prefered the later XLT and Tipos, Hippo Tipo and EU-1A).