Skins

Skins are a kind of posts, being made in normal, slim, x128, and Skin Packs.

Creation
Once you press Skin, all of the mentioned options will show up.

Skin Packs
When you press Skin Packs, it will allow you to make normal, slim, and x128.

Posts
Skins are also a type of posting activity that exists and thrives in almost all Minecraft mod making platforms, as well as Crafty Craft. A skin is what a player wears in game, like Steve and Alex skins.

Trivia

 * The UI of Skin Packs did not update with Addons in version 14.1.
 * It did update in version 14.3
 * Skin Packs is the first post type to have options for the type (Normal, Slim, x128, and Skin Packs), the second (and currently only other one) is maps (with each world you have).