ブックタイトルConservation and Restoration of Western Paper

概要

Conservation and Restoration of Western Paper

The greatest benefits are achieved whenthe ink is insoluble and the artifact can besafely washed, treated with phytate anddeacidified. Water soluble iron (II) ionsand sulfuric acid and soluble deteriorationcomponents are removed. Deacidificationneutralizes sulfuric acid and providesalkaline reserve (Diagram 5). Alterationof colour, ink surface, bleeding and furthermechanical damage remain a risk, andtreatment must be carefully monitored(Diagram 6).When full treatment cannot be carriedout, local repairs should be executed with aslittle moisture as possible, so as not to causethe iron (II) ions and acids in the ink tomigrate into the surrounding paper 9 . Repairtissues that are reactivated with solvent, suchas those coated with Klucel G, can lowerthe risk of acid migration. Other researchconcludes that the use of re-moistenabletissues made with type B gelatin with a highor medium Bloom degree may also protectthe paper and the ink against degradationcaused by oxidation because of the gelatin’scapacity to encapsulate free iron (II) ions,making them inert 10 (Photos 18a-c). Whenchemical treatments are not an option,interleaving with paper impregnated with adeacidification agent and an antioxidant canbe considered. 11Letterpress copybooks are prone to highrates of degradation. They are an early formof a document copying process commonfrom the turn of the nineteenth centuryand used through the 1950s, and are animportant source of information relating toour cultural history. The process involved thetransfer of ink on a freshly written documentto a moistened sheet of thin copying paperthrough the use of direct contact andpres￢sure, leaving a mirror image print tobe read from the verso of the thin paper.These artifacts are subject to damage frommechanical manipulation. Because of theadvanced state of deterioration, the paperscan only be repaired with a remoistenabletissue in order for them to be handled fordigitization (Photos 19a-d).The Altona Haggadah, from the JacobLowy Judaica special collection, is abeautifully illustrated manuscript datingfrom 1763 that was brought to the labfor assessment. Although areas of ironIRON GALL INK TREATMENT BENEFITSWASHINGCALCIUM PHYTATE CHELATIONDEACIDIFICATION? Water soluble iron (II) ions and sulfuric acid are removed? Soluble deterioration products are washed out? Fibre-to-fibre bonding is reactivated? Paper may appear more flexible and brighter after washing? Calcium phytate can arrest the oxidation process by binding complex iron (II)and iron (III) ions? Iron phytate complexes are stable and do not harm the iron gall ink? Sulfuric acid will be neutralized by deacidification? Gives and alkaline reserve for long term protection from acid hydrolysis? Prevents oxidation of ink in the short term; iron (II) ions are oxidized inalkaline conditions to iron (III) ions?they do not catalyse oxidation, butprocess is slowly reversedDiagram 5 Iron gall ink treatment benefits68