Back in high school, I played around with microfilm on indoor models. Lightly thinned Aerogloss dope, a drop of glycerine or castor, I forget which, poured over a water surface, like a bathtub of water. Let you build things like a 39" span indoor rubber Free Flight planes, 8" or 9" chord, with a total weight under 10 grams (< 1/3 ounce?). Or a couple fly powered indoor models like the Bill Winter article in an old late 50s Flying Models magazine. Dope heavier than plastic film?

Last time I talked with the late Gerry Skrjnc of Micro-X models, he gave me a couple square feet of a plastic film that was supposed to be slightly lighter than that microfilm. At the time, I was proud of an 8 gram E-Z Bee from one of his kits. Then he showed me his, same kit, 4.5 grams.

As far as the relative weight of Silk/Dope or Tissue/dope, that will depend on the amount of dope applied, how much thinning, how much sanding/polishing, and even, like the chart shows with Mono, how much of what color dope is used. Most free flighters I know still prefer to use a colored tissue or silk with just enough clear sanded dope to seal the weave of the material.

Still don't think I've ever seen a mirror finish with film like I've seen with fabric/dope.

The above is true. However, there is a cost associated with paint. In the case of some competition u-control models, I've heard numbers in the $125 to $150 for the materials! Their finishes are really super and usually very light!

Paul

And those Control Line Concours de' Elegance finishes can also take close to a month or more, with waiting for the finish solvents to outgas before the final sanding and polishing.

I thought it interesting the variation from one batch of Mono red to another. What was it, 5.7 oz/sq ft to over 9? At the 9 oz, that would put the finish weight about the same as the silk with 14 coats. But then again, how much sanding and polishing went into that silk/dope sample? Also, how long was given for the solvents to fully evaporate before weighing?

I sometimes fly in FAC competition. For lightness, normal finish is done with dyed or colored lightweight tissue. Thinned paint may be used for trim and markings, or the trim and markings are cut from other colors of tissue and applied using dope as an adhesive. In fact a number of competitors actually print off their covering with markings on an inkjet printer. Very effective and time saving for WW-1 lozenge patterns. One or two coats of thined Nitrate dope for fixing the color. Lot of the glow powered Free Flights are done this way too. Lighter than most films, and more temperature stable as well. Never see coverings sag. Also adds strength to the structure.
This would be an interesting expirement to do for this discussion. Build a couple (300 - 500 sq in) profile control liners, or maybe even a couple identical medium sized (300 - 500 sq in) radio jobs, ballast them so the uncovered frames weigh the same on a sensitive scale, cover each of them with a similar pattern, one with dope/silk or dope/tissue methods, cover the other with Mono or another film and then see which one is heavier when done.

Judged a number of static Mall Shows. Best finish awards always went to a doped finish. After a couple years, we decided to have a best traditional finish and a best film finish, just to give the film guys a chance at a prize. Did see a film covered model that was competitive with the best traditional, once. We could have sworn the plane (a 1/2A RC job was finished with tissue/dope. The trim looked like it had been painted on, even the trim on the nose of the wheel pants. Builder admitted that he builds, his wife covers. He couldn't do that kind of job to save his life.