This increases until the item is 100% cured, where the item will automatically become a fully cured and ready for crafting use.
As these raw items continue to lay on the floor indoors, they will display a 'X% Cured' progress by looking at the item, showing their current status till becoming fully cured. These items may be cured by dropping them on the floor or otherwise placing them inside an 'indoors' location (most caves and artificial structures, including many without a Loading Transition, such as the Stone Church and Mountaineer's Hut). Some raw resources from plants and animals cannot be used for crafting in their initial state, and must first be cured: these include Birch Sapling and Maple Sapling, all types of Animal Pelts, and Fresh Guts from animals. Curing is a mechanic in The Long Dark, which converts raw resources into crafting items.
