Treatment Services
Dry Cleaning
The process used to remove surface dust, dirt, and debris is called dry cleaning. Conservation-grade vulcanized rubber dry-cleaning sponges, “soot sponges,” brushes, eraser crumbs, and blocks are used to dry clean paper items. Accretions, insect specks, and mold residues are normally removed by scalpels, aspirators, or specialized vacuums.
Removal of Previous Repairs or Tape
In the past, repairs were often made using materials we now know to be harmful to paper, such as commercial tapes and adhesives that stain. Repairs can be removed using moisture, in a water bath, with poultices, mechanically, or using heat. Synthetic adhesives and pressure-sensitive tapes and adhesives are usually softened with an organic solvent before they can be removed.
Mending
Tears are carefully aligned and then repaired, usually on the reverse, with narrow strips of mending tissue. These strips are pasted over the tears using a non-staining, archival starch paste or methyl cellulose. Sometimes a synthetic adhesive such as heat set tissue is used when an artifact cannot tolerate moisture.
Fill Areas of Paper Loss
Holes or paper losses may be filled individually with lightweight papers, paper pulp, or with a paper carefully chosen to match the original in weight, texture, and color.
Washing
Water washing is often beneficial to paper. Washing not only removes dirt and aids in stain reduction, but it can also wash out acidic compounds and other degradation products that have built up int he paper. Washing can relax brittle or distorted paper and aid in flattening. All media are carefully tested beforehand for water sensitivity. When materials permit, objects are immersed in filtered water. On occasion, a carefully controlled amount of chemical compound material is added to the water to assist in the cleaning process and in the neutralization and removal of acids.
Humidification is performed to relax paper fibers and make it more supple for flattening. It can be done in a variety of ways, including misting with an atomizer, slowly introducing moisture through Gortex, and full submersion in water.
Humidification
Flattening always follows aqueous treatment. it is usually performed between blotters or felts under moderate pressure. Flattening can also be performed dry for moisture sensitive items by putting items under weight or in a nipping press. This process reduces creasing and distortions which often plague paper.
Flattening
Deacidification, or Alkalization, can be performed by spraying a paper object with alkalizing spray, by immersing it in an aqueous solution of an alkaline substance such as magnesium or calcium hydroxide.
Deacidification
Weak or brittle papers or sheets with numerous tears may be reinforced by backing them with another sheet of paper. Archival tissue of high-quality cellulose fibers is the usual lining material. The backing is adhered with a dilute starch-based paste or methyl cellulose. Some previous backings may need to be removed due to the degredation of the backing material such as ground wood pulp or non-archival adhesives.
Lining
When absolutely necessary, flaking or friable media are consolidated with an appropriate natural or synthetic material to stop or retard ongoing loss.
Consolidation
If an object has been backed with a support that is not part of its original structure and the backing is destructive or inadequate, it should be removed if possible. Backing removal can be done in a water bath or through mechanical means.