Sealing is a procedure in which a sealing item (such as Incomplete Stamps of Binding and Seal Stamps) is used to subdue the magics that bind a particular item to a player character. This allows an item which has the tag Binds when Obtained to be tradable, at the cost of the item being unusable until the seal has been removed. Sealed items have a red circular mark on the upper right edge of the item icon border.
Sealing an item requires a particular amount of sealing items which depend on the rarity and type of item. To perform a sealing on an item, right-click on the desired sealing item and right-click the item to be sealed when the sealing window appears. Upon confirming the sealing procedure, a sound effect along with a message on the message window "<name of item> has been sealed." would denote the success of the item; if it fails, the message "<name of item> has not been sealed." will be shown, and the sealing items will be consumed regardless of the results.
Not all items with the Binds when Obtained tag can be sealed. For example, Cash Items and heraldries that have not been crafted cannot be sealed despite having the tag. There is also a limit as to how many times an item can be sealed, which is indicated on the item's information window as "Seal: up to x times".