The tarp is an item that can be found as is randomly placed in the Miscreated world. Other locations may have tarp-covered boxes in which there is a potential to loot a tarp. Tarps are not stackable and each one carried will take up one storage slot. The only color tarp available is blue.
Tarps covering boxes which are potentially lootable can typically be found at the airfield on the cargo aircraft or in industrial type warehouses.
The tarp is combined with a 200 L Water Barrel to craft a Water Collector. A water collector will collect Clean Water when it rains, however, the water will change to Strange Water if an irradiating storm passes over. The water collector will hold up to 200 L of water.
The crafting recipe can be found in the Basebuild menu under the Utilities sub-heading.