In general: if you kill a monster with a body part that has some known (or suspected) property, is there any mechanic around harvesting the body part and using it as-is (or with minimal processing required)?

Specifically: We're fairly low level and just found ourselves fighting a Dretch. While none of us did very well on our knowledge checks, it became apparent during the fight that it had a fair number of buffs, including DR and elemental resistances.


Which of these are properties of the skin, and which are properties of the creature itself?
Would such properties persist in the skin after removal (and tanning, I assume)?
Would tanning/crafting produce armor, a wondrous item, a trophy, or what?


I read some comments about how his is sort of frowned upon since it disrupts the economics of the game... and, ultimately, I understand this is totally subject to DM's approval, but... just thought knowing how this is handled generally is appreciated.

(I asked another question about repurposing magic items which is somewhat similar to this, but I don't think this is a duplicate, since this is specifically about harvesting nearly-ready-to-use parts of creatures, whereas the other one dealt mainly with using magic items to create new items).


Question: Is there a list of punctuation commands for iPad dictation?
Answer: Siri dictation is never going to be 100% accurate and the easiest way to get the result you want may be to edit the text by hand after you've dictated the body of the message.

Jim Rhoades provides a useful list of Siri dictation commands.