So you want to chemically treat an animal skin to make it near-impervious to decay? Try this:
  1. Get a cow. Or a calf. Or sheep. A goat, lamb, kid, horse, pig, kangaroo, deer, reptile, seal, or walrus will also do, just make sure you're not violating the Endangered Species Act.
  2. Skin it.
  3. Cure the skin with wet salt or brine.
  4. Soak in water to remove salt, dirt, blood, bits of muscle and sinew, etc.
  5. Separate the skin from any inner surface.
  6. Scrape hair off, either mechanically or with a dull knife (You may wish to make this process easier by soaking the skin in a solution of lime and water containing a small amount of sodium sulfide for a few days).
  7. Delime the skins, if necessary, with a weak acid bath.
  8. Treat with a bating material if you wish your skin to be supple and flexible.
  9. Tan the skin, either with tannin, in a series of increasingly concentrated solutions, or with a chromium-sulfate solution (pickle the bated skin first in a salt and acid mixture) by immersion.
  10. Infuse with oil, grease, wax, and/or dye.
  11. Let dry.
  12. Brush, sand, or varnish to your desired finish.
You've got leather!

And this, from the lame joke department:

Useful word for this punchline: "Leather? Leather? I don't even know her!"

Repeat until you get a laugh. Especially if you're the kind of person who is desperate for attention.

Somebody slap me please.