=== GUI ===
[[File:Bundle usage.png|thumb|Hovering over a quarter-full bundle with 16 items.]]
Hovering over a bundle reveals its blue fullness bar. When the bundle is empty, the fullness bar says "Empty" and shows the description, "Can hold a mixed stack of items". If it's completely full, the fullness bar turns red and says "Full". When there is at least one item in a bundle, space will open up above the bar, which displays the items in the bundle's slots, sorted by how recently they were added, from right to left. The space where the slots are shown is only wide enough for four slots, so additional space opens up for new rows. When there are more than three rows, only the top three will be displayed, and the bottom-right slot will be replaced by text that says, +<number of slots hidden>, where the slot replaced by the text counts toward that number.

Bundles show an additional fullness bar on their icons, in a similar way to how items that take damage show their durability. Bundle fullness bars are blue, or red when full, and appear when the bundle contains at least one item.
