Reinforced tissue

I wouldn't bother with photocopier paper: its made of fairly short fibres, which means its weak, and full of inert fillers which are heavy and don't add any strength. Finally, nitrocellulose dope won't penetrate it very easily. The better answer is to dope on another layer of tissue when the first is dry. The dope in both layers will stick together and proper model covering tissue is strong for its weight due to the longer fibres in it. In the days when you could still buy both heavy and light modelspan we knew that double covering a wing with two layers of light modelspan was easier, stronger and lighter than using a single layer of heavy model span. As a bonus, you get a much smoother surface too. Some covering tips:

- don't use the dope at full strength. Thinning it 50:50 with cellulose thinners makes it a lot easier to work with because it wets the tissue more easily. Two or three coats of 50:50 dope will completely fill the pinholes in the tissue.

- wetting the tissue with a damp cloth or spraying it with water will make wrinkle-free covering much easier. Or, put the tissue on dry using dope to stick it to the framework. When the dope has dried, spray the tissue with water. Let it dry out completely, which gives a nice, smooth covering, and only then brush on the first coat of dope. Let each layer dry and the solvent evaporate before applying the next. One coat a day gives a much better result than two or three in a day.

- well doped tissue is extremely weatherproof - over the years balsa and tissue models have been flown on ice and in rain during competitions many, many times. If they are well doped you get little or no water in the wings even when its pissing down.

In case you're wondering, I'm not suggesting the above to save weight though it will. I still think weight is fairly irrelevant to your mission compared with the strength and torsional stiffness of the airframe. Properly doped double covering adds a lot of stiffness. You'll be surprised how much stiffer a tissue covered wing is compared with the bare structure.