Backup objects for fully provisioned volumes with thin lists of chunk signatures

Examples may include backup objects for fully provisioned volumes with thin lists of chunk signatures. Examples may generate one or more full lists of chunk signatures for the address space of a fully provisioned volume, compare each chunk signature of the full list to an unused region chunk signature representing a chunk of an unused region of the fully provisioned volume, generate metadata to indicate used regions of the fully provisioned volume, based on the comparisons, and generate from the one or more full lists, one or more thin lists omitting all chunk signatures determined to match the unused region chunk signature.