Record of pre-treatment condition

Before treatment, the paper quality and condition of the materials are confirmed and recorded. Moreover, a non-destructive analysis is performed to ensure the correct treatment.
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The condition of the binding is recorded
The pH value is checked before treatment
The type of material group is investigated
Visual materials are checked for water- or solvent-resistance

Non-destructive analysis
Analysis is conducted without taking samples, such as observation of the paper's fiber composition or pH value, etc.


Dry-cleaning refers to the removal of dust on the surface of the material or between the paper fibers by brush, eraser (plastic, rubber or powder, etc.), and suction table. Dry-cleaning is carried out first to prevent the absorption of dust during wet-cleaning.
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Removal of dirt between fibers by suction
Use of the soft putty eraser
Dirt removal by suction
Dirt removal by suction

Suction table
A vacuum table that uniformly draws air between many layers of flat mesh.

Treatment for mold and insect excrement

After removing general mold and insect excrement by suction, etc., badly affected areas are treated by hand. Active mold is sterilized with waterless alcohol. Mold and insect damage, however, can re-occur unless the storage environment is changed.
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Insect excrement left after insect damage
Insect excrement
Sterilizing mold
Removing mold by suction

Waterless alcohol
99.5% alcohol. For water-resistant materials, the optimal concentration to sterilize mold is 70%.

Removal of damaging elements

Previous inappropriate repair elements such as adhesives, staples or metal clips, etc., that could continue to cause damage to the materials are removed. Damage-causing elements can be removed in various ways. Water-soluble glue can be removed by altering the condition of the water it is soaked in, while most composite glues and pressure-sensitive adhesive tape can be removed with anhydrous alcohol or organic solvents. The residual repair material can be removed using the suction table.
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Staple removal
Removal of inappropriate lining papers
Removal of inappropriate adhesive
Removal of cellophane tape

Pressure-sensitive tape
Adhesive tape such as cellophane tape that adheres when pressure is applied. It was developed in the mid-19th century.
Organic solvents
General term for the group of volatile compounds that dissolves non-water-soluble materials at room temperature.

Wet-cleaning and flattening

Wet cleaning refers to cleaning with liquids such as deionized water, weak alkaline water, warm water, etc, according to the material. This method washes out harmful metal ions and acids in the paper, and also improves the whiteness and flexibility of the paper.
Flattening uses water, alcohol, etc., to return paper to its original flat condition.
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Testing water-resistance before treatment with water or alcohol
Washing out acids or other harmful substances in the paper
Flattening (using suction table)

Deionized water
Water that has had all impurities, metal ions, etc., removed. Pure water.
Weak alkaline water
Pure water with added magnesium and calcium.
Metal ion
Iron or copper ions that can damage paper.


 2001 Paper Documents Conservation Studio,Inc. All rights reserved.