what is the airship( helium/hydrogen) skin made of?

Question

nylon, polyester, mylar?

Answer 1

In the old days of the Hindenburg it was skinned in cotton, doped with iron oxide and cellulose acetate butyrate impregnated with aluminum powder.
http://en.allexperts.com/e/h/hi/hindenburg_(airship).htm

A high tech skin is made from lots of different layers like this
http://www.sstd.rl.ac.uk/Appleton_Space_Conference/Pattinson.pdf
using different layers for strength and helium barriers.

Here is an extract of a patent
"A preferred skin material is Dacron of about two ounces per yard. A highly reflective material 70 should be installed on the upper outside 72 of the fuselage 12 to reflect energy from the sun. This will assist with internal temperature regulation and thereby prevent unwanted changes in pressure and buoyancy."

Answer 2

Ive find 2 resources :
1)in recent years balloons made of metal films have become popular. The manufacturing process of these balloons is very different. They are made from a sandwich of two swatches of mylar—a polyester film—often circular in shape, which are sealed together around the edges.
2)The envelope(in airships) is usually made of a combination of man-made materials: Dacron, polyester, Mylar, and/or Tedlar bonded with Hytrel. The high-tech, weather-resistant plastic film is laminated to a rip-stop polyester fabric. The envelope's fabric also protects against ultraviolet light. Usually the envelope is smaller than the bladder to ensure that the envelope takes the load when the blimp is fully inflated. The bladder is made of a thin leak-resistant polyurethane plastic film.

Answer 3

It varies depending on if it is a rigid or non-rigid dirigible/zeppelin.

Some use various types of fabric, and rely on a higher pressure gas.

Some use thin aluminum sheeting, but there are usually still fabric gas bags inside.

Answer 4

a gelatin and latex compound