Originally Posted by jeromestyle
from most exclusive to least and
from highest quality to least.
Calfskin, Goatskin, Lambskin and Pigskin.
Calfskin is the firmest and the best suited to shoemaking.
Pigskin if tanned correctly is tough and makes a good shoe although it is very porous.
Goatskin is an older version of kidskin. It is fairly delicate and is prone to "peeling" although not as much as kid and maybe not as much as in earlier years. Most women's shoes are made of kid or goat.
Lambskin is the most delicate of the four. I would not recommend it for any shoemaking purpose. It peels readily and the grain surface is very soft...meaning it has little or no abrasion or puncture resistance. Because the grain surface is so soft, I don't think I've ever seen a lambskin that had a finish coat on it. Mostly naked grain...maybe some wax. It is often used for a light suede for women's shoes.
Think of the animal...the environment it lives in. The purposes for which it is bred and raised. The age and size of the animal. Those things will tell you a great deal about the quality of the leather without even seeing it.
As far as "exclusivity" is concerned, none of the four are uncommon. So then it comes down to tannages, finish and purpose. Best quality calfskin would be premium in any shoemaking context.