Mass conservation preserves many books and documents with the same problems, which reduces the cost of treatment and individual handling. Given the great variety of material found in archival material that would require sorting and separate treatments, mass conservation is more often applied to library material than archival material. The only mass conservation treatment that can realistically be applied to archival material is preventive conservation by means of temperature and humidity-controlled environments.[55] However, if archival material is sorted by material type, batch treatment can be applied to low to moderate value items.