The constant, arid climate of the Dead Sea area, which is about 400 meters below sea level, was probably the major factor contributing to the preservation of documents for two millennia until the removal of the first scrolls from their hiding place in 1947 and their transfer to Jerusalem. Indeed, the drastic change in climatic conditions rendered them vulnerable to damage. Jerusalem, at about 800 meters above sea level, has an extremely different climate from the Judean Desert.

The scrolls were at first unknowingly handled inappropriately and kept in an uncontrolled environment. Moreover, in the first years, adhesive tape used to join fragments and seal cracks caused irreversible damage. The scrolls were then moistened and flattened loosely between plates of window glass and sealed with adhesive tape. The ageing of the adhesives and the pressure of the glass caused the skins to darken – to the extent that some of the texts are no longer legible – and the edges to gelatinize.

In the 1970s, a team of conservators from the Israel Museum began to treat some of the fragments: the adhesive tape and some of the stains were removed, the fragments were reinforced and the glass plates were replaced with cardboard. It became evident, however, that the degree of deterioration that had set in called for more urgent steps to be taken. In 1991, a climate-controlled storeroom and laboratory for the conservation and preservation of the scrolls were set up by the Israel Antiquities Authority in the Rockefeller Museum building in Jerusalem, where four conservators are engaged full-time to preserve the scrolls.

Detailed descriptions of the condition of each fragment are recorded; they include photography and mapping of each fragment, no matter how minuscule. However, the most time-consuming task remains the removal of the adhesive tape. Tape adhesive is loosened by water-based adhesives and a dry poulticing material is useful in the removal of the tape residues and stains. After the removal of the remains of the adhesive tape, oils and other stains are cleaned, and the back of the scroll is reinforced wherever necessary. This operation cannot be standardized and each of the thousands of extant fragments needs individual attention. The preserved fragments are arranged on acid-free cardboards, attached with hinges of Japanese tissue paper and stored in solanders in the climate-controlled storeroom.

While preparing the scrolls for exhibition, a new housing system was devised. The fragments are sewn between two layers of polyester net stretched in acid-free mounts. These in turn are enclosed in a frame made of polycarbonate plates. Unfortunately, the process of aging cannot be halted. We are striving to slow it down with as little intervention as possible, employing reversible methods. The conservation and preservation procedures are extremely lengthy and costly. But the Dead Sea Scrolls are a universal cultural heritage, which must be saved for future generations.