Polymorphing a dragon corpse creates a random object made of dragonhide.

Dragonhide gear resists attempts to enchant it a significant percentage of the time, so it takes more resources overall to enchant it up to the same level as a non-dragonhide piece of gear.

Dragonhide gear naturally deteriorates gradually over time, and the only way to prevent this is to rub large quantities of gold on it, which destroys the gold.

Rather than having dragonhide items be generically “dragonhide”, let them each be a certain dragon color, which cannot be specified by wishing. This item does not confer the same extrinsic it would if it were body armor. Instead, when you are wearing dragon scales or mail and a dragonhide item of the same color in another slot, you gain a very powerful extrinsic which cannot be gained otherwise. E.g. cancellation immunity for gray dragon armor.

The idea is to discourage everyone continuing to wear gray or silver dragon scale mail: if you find or wish for dragonhide gear and get some other color, it may be attractive to wear dragon scale mail of that color instead in order to get the powerful extrinsic.

When you wish for anything made of dragonhide, there is a chance that an incensed Tiamat shows up to kill you over it. The more things you wish for that are dragonhide, the higher the odds of this happening.

Dragonhide bags of tricks only spawn dragons. (Though this would include baby dragons, so it would probably at least approximate being level-appropriate).

The game should award an achievement for ascending with a full set of dragonhide armor (a dragonhide piece of gear in all six armor slots).

Dragon scales can be enchanted into dragonhide gear that is not scale mail.