Black Panther Skin Farming Location
Black Panther Skins drop from the Panther enemies which are found roaming around the forest areas of Wakening Lands. Keep in mind that the Haze Panthers are a different beast entirely and will drop Haze Panther Skins, used to create Haze Panther Gear instead. Panthers drop Black Panther Skins.
The Black Panther Skin we're after has about a 30% chance of dropping off each defeated Panther. To make matters worse, Panthers are also fairly uncommon throughout the zone and are difficult to come across. You should expect to spend a lot of time farming in this zone.
There are a few upsides to farming here though, in addition to hunting both types of Panther enemies you'll also want to keep an eye out for Holgresh enemies, which drop Holgresh Fur and Tigeraptors which drop Tigeraptor Hides. The Holgresh Fur is used in creating Holgresh Fur Gear, which can get you to 300 Tailoring as well.
Tigeraptor Hides are used in creating Tigeraptor Gear which is another available route to raising your Tailoring if you can't get your hands on enough panther skins.
For a list of all Tailoring Recipes that you can make with Black Panther Skins follow the link provided. Many of these are required for reaching 350 Tailoring and are part of my 350 Tailoring Guide.