Soulbound

Soulbound is a mechanic in SkyBlock that binds an item to your profile. Once an item is Soulbound, it cannot be sold to NPCs,auctioned, or traded with other players apart from your co-op members.

To mark an item as Soulbound, one must donate them to the Museum. Upon donating an item, you can take it back. However, it will no longer count towards your museum value.

Most of Bingo and Crimson Isle content, such as most mob drops, crafted armor, and loot from the bosses, are automatically Soulbound.