Stackability is the ability of food packaging — cases, crates, cartons, or palletised loads — to be stacked on top of one another for storage and transport without collapsing, crushing the product, or wasting space. Good stackability depends on the strength and rigidity of the packaging material, the shape and weight distribution of the pack, and features such as interlocking bases, reinforced corners, and flat tops. For manufacturers and retailers it matters because warehouse space and lorry capacity cost money: packs that stack neatly and safely allow more product per pallet and fewer damaged goods. Test methods include compression testing, where a pack is loaded until it fails, to set safe stacking heights.