What sizes can full item stacks be?
No, all items will stack to either 64, 16 or cannot stack.Most items can stack up to a maximum of 64 in one slot. Tools (with the exception of clocks and compasses) cannot be stacked. Certain items, such as Snowballs, Buckets, Eggs, Signs and Ender Pearls are special and can only stack up to 16.
This is for vanilla Minecraft (no mods) only! Items from mods can have any stack size.