ItemStacks

Itemstacks are how individual items are represented in Minecraft. Quite simple, it's a stack of items ItemStacks are used in Tinkers' Modifiers to determine the items required to add a modifier to a tool

JSON Form

ItemStacks are represented in JSON using a dictionary ({}) like so: { "item":"minecraft:apple", "damage":0 } In all cases, "item" is a required key with a string value, and "damage" or "meta" is an optional key with an integer value, defaulting to 0. Negative "damage" values get turned into a wildcard, therefore accepting any metadata or damage value