Chapter 3 Rescuing Paper Materials

Chapter 3

Rescuing Paper Materials
Part 2▧ AMANO Masashi (National Museum of Japanese History)

Introduction
The paper materials covered in this chapter refer to records generated and accumulated by people during their lives. These materials, mainly written records,
are made of various types of paper depending on the period and purpose, ranging
from old documents with recognized historical and cultural value to everyday
memos and journals. A vast, diverse group of materials remains across Japan.
While many public institutions such as museums, libraries, and archives holdpaper materials, individuals have enormous materials at home, which they haveinherited from ancestors to convey the history of the community and the family.
They come in records maintained by organizations, personal diaries, writings, andbooks. However, in most cases, the owners treat them as a group, so in a disaster,
those who rescue them must handle a massive amount at once; in such cases, theymust accurately identify and treat water-damaged materials.

1. Rescuing Damaged Paper Materials
If a disaster damages the storage space, materials not contained in containers
are at risk of being scattered. In addition, a tsunami or torrential rains can deteriorate paper materials—easily contain water—due to decay and mould, destroying
some of the text and other material information, and even the materials themselves [Fig. 1: Materials damaged by tsunamis (rescued on 23 March, 2012)].

37

Letters and documents are sometimes stored as a group of several
items, tied together with string or inenvelopes and bags. The custodian
may have organized them by age andcontents when storing them. In a regular organization of materials, the practitioner needs to record the conditionand structure of the materials before
transportation; it is fundamental toorganize the materials while retaining
Fig. 1
their original shape and arrangement,
as the storage space per se is essential
information.
However, it is difficult to make such detailed records following these basic
principles in a disaster because of the need to transport materials rapidly within alimited time. Therefore, it is desirable to record the on-site removal process withphotographs or videos and keep them as reference information for later organization work. As for paper materials, it is not easy to determine whether they arehistorical at the on-site work stage. Usually, it is impossible to immediately grasp
information on materials at the disaster site due to water damage or mud stains.
Saving as many materials as possible requires removing them first and then sorting them out while grasping their contents during the first aid phase.
When handling, the practitioner should be careful to avoid damage or dissipation of the materials, as they are vulnerable when wet. Since most paper materials
are groups of records accumulated by a house or organization, they are generally
stored as a single group, often in boxes or containers. When transporting, it isnecessary to keep them together as much as possible, and if stored in a container,
move the container itself; if not, the practitioner needs to put them into plasticbags or cardboard boxes before transportation. The order should be maintained,
but it is challenging to maintain detailed order under limited circumstances, so it
is necessary to record the condition with photos or videos before transferring.

38

Chapter 3 Rescuing Paper Materials

2. Condition Assessment and Temporary Storage
2.1. Grasping the Condition(1) Approximate Number of Materials

Precisely counting the number of materials at the rescue stage is almost
impossible: check the approximate number of items for planning the work
process. Paper materials are usually lie in containers, so it is necessary to
carry them as they are. Otherwise, put the materials into containers like cardboard boxes and count the number of the containers. In addition, check theforms of materials (books, documents, letters, postcards, coated paper) as
best as possible.
(2) Water Damage
Determine the cause of water damage: rainfall, storm surge, tsunami,
river, or moisture or leakage at the storage location. We can focus on dealing
with the water in the case of rainfall or moisture. However, river or sea water
may contain contaminants which need work other than drying.
Check the extent of the damage, whether entirely or partially, and see
whether the water is so wet that it is dripping or has already started to dry.
(3) Damage level
Confirm mould, rot, odour, and paper adhesion. However, at this point,see only the extent of the damage seen by surface observation. Mould, decay, and odour can pose health hazards, so avoid putting your face too close
to the material. Adherence can break the material if wet. Do not separate thesheets forcibly.

39Part 2

Dealing with damaged paper materials requires the practitioner to confirm
the presence or absence of breakage and water damage. Earthquakes can tearor break the paper materials, while water damage by rainfall, storm surges, andtsunamis sometimes destroy them, too. We should not leave them unattended, orwater damage will lead to decay and mould, making it impossible to maintain andpass on the materials as historical ones. Therefore, the practitioner must check thefollowing points.

2.2. Temporary Storage After
Transportation
Storing water-damaged materials
at room temperature will cause themto rot; dry them as quickly as possible.
If the total number is under 100, it
may be possible to dry them immediately after transportation. However,many items need preparations fortreatment, and immediate response
becomes difficult. Frozen storage
using a freezer is sometimes necessaryduring the preparation for treatment[Fig. 2: Frozen-stored water-damaged
materials].
The advantage of frozen storageis that it can control decay and deteriFig. 2
oration, including biological damage.
During frequent typhoons, high temperature and humidity aggravate the risk of rapid decay; temporary freezing andstorage make it possible to adjust work timing, for example, to conduct full-scale
work after the weather becomes cooler and drier.
If possible, pack each item in a plastic bag and frozen. However, if theitems are in too poor a condition to separate one another, pack them in a plastic
bag and frozen as a whole. Since it is not easy to immediately secure a large
freezer, it is advisable to identify nearby facilities with large freezers before adisaster and ask them to cooperate in an emergency.

3. First Aid Measures for Damaged Paper Materials
Regarding the first aid measures of paper materials, many practical examples
of disaster countermeasures and manuals are available in Japan and abroad, introducing detailed process techniques. This chapter focuses on the required response
and the concept of first aid rather than presenting specific techniques.

40Chapter 3 Rescuing Paper Materials

One of the goals of such measures is to prepare for the data recording: countthe number of materials and eradicate major concerns—decay, breakage, or
mould—about storing and managing at average temperatures. Drying, cleaning,
and adherence separation are necessary.

The drying process is the highest priority. However, we use different methods
depending on the condition and scale of the materials and the number of practitioners. Methods practised or introduced are diverse and come into three patterns
regarding methodology and purpose.
The first is air drying [Fig. 3: Air-Drying (Hiroshima Prefectural Archives, 30
July, 2018)]. Practitioners spread the materials in a space out of direct sunlightand dry them with natural air or a circulator. This method is more cost-effective
and technically feasible than others. However, considering the risk of spoilage,
it is most effective when dealing with materials with only minor mould or stains
and just beginning to dry out.
Next comes water absorption drying [Fig. 4: Water Absorbent Drying (1):
Wrapping materials in absorbent paper (Hiroshima Prefectural Archives. 11
December, 2018), Fig. 5: Water Absorbent Drying (2): Degassing in a pouch (Hi-

Low

Disaster

High

Transportation

Urgency
Expertise

Frozen Storage(if necessary)
Vacuum FreezeAir-Drying
DryingCleaning
Condition Recording (Condition Check)

Dismantling(Recording)High

Washing

first aid
Difficult to
Respond
Immediately
Sorting

Restoration

Low

Restoration
Examination/
Implementation

Re-Organization
and Preservation

Workflow after rescue

41

Part 23.1. DryingFig. 3Fig. 4

Fig. 542

Chapter 3 Rescuing Paper Materials

43

Part 2roshima Prefectural Archives. December 12, 2018)]. Some researchers have recently proposed specific processes with various practical examples. However, thebasic concept is the same: wrap materials in absorbent paper and squeeze out the
moisture by applying pressure. This method is effective for materials containing alarge amount of water. It can effectively extract water by wrapping each material
or a single mass of materials in absorbent paper and applying pressure.
When handling large quantities, it is possible to squeeze out the moisture byplacing the material in a pouch and deaerating it with a vacuum cleaner.
Water absorption drying alone takes a long. Therefore, this method is usuallyused for the preparation of air drying. When they can open the adhered paperroughly, the practitioners use air drying.
The third method is vacuum freeze drying. This method is large-scale, uses
vacuum freeze-drying equipment, and effectively handles large volumes ofmaterials (more than several thousand). In Japan, researchers used this method
for the first time in 1992 in Soka, Saitama, to dry materials damaged by water
due to a private house fire and firefighting activities. Since then, researchers haveused this method for large-scale water damage, but it is not a silver bullet because
coordination with facilities that own equipment is necessary and the cost is not
low. Therefore, when we anticipate a large-scale disaster, we must coordinate inadvance with nearby museums and research institutions that own the equipment.
As described above, several methods are available for drying materials. However, selecting a technique that suits the situation and purpose is necessary rather
than sticking to a specific one. Generally, when working manually, it is vital to
avoid applying heat or other methods that may damage the materials and to avoid
rapid temperature changes. In addition, coated paper sheets may adhere to one
another too firmly if dried thoroughly.
In any case, it is often difficult to dry the materials completely using only one
method. Combining several ways depending on the condition of the materials andthe workforce is necessary.
For example, see the practice after the torrential rains in western Japan in
2018. The torrential rains caused water damage to several thousand paper materials (account books, postcards, letters, and paintings) stored in private homes
in Hiroshima. The Hiroshima Prefectural Archive accepted these materials andcarried out the drying process according to the following procedures.

Selecting an Appropriate Drying Method

Air-Drying

◎

Cost

Work

△

Efficiency

Versatility
Anticipated
Usage

◎

Water Absorbent

Vacuum Freeze-○△

Drying△○Minimal mould

Temporarywater damage

drying; used whenand staining/minor

treatment for air-Drying◎△In the case ofextensive damage

the material has a
lot of moisture(1) Classification

First, they classified the materials by genre (account books, pamphlets,
postcards, letters, and paintings).
Then they sorted the classified materials into three categories: (a) thosecontaining a large amount of water and are at a severe risk of decay, (b)those beginning to dry out, and (c) those already dry and with no evidence ofwater damage.
(2) Treatment(a) They wrapped each item in a plastic bag, put them in a cardboard box toprevent odour and moisture, and stored them frozen.
(b) They prepared shelves and air-dried the materials in a well-ventilated
place out of direct sunlight.
(c) They cleaned the materials after checking the mould and staining. At thisstage, they focused on adherence separation described below rather thanstain removal, confirming that they are dry to the depths.
(3) Thawing and Drying of Frozen Materials
For (a), since it was summer, they froze 17 cardboard boxes and stored
them until when spoilage was less likely to progress. When winter came,they started the drying process.
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Chapter 3 Rescuing Paper Materials

Condition As of 30 July

Part 2

Partial air-drying at unpacking yard in Hiroshima Prefectural Archives
Groups of materials with different degrees of decay progression and dryness[1] Cold Storage[2] Continuing Air-Drying

10-13 December, 2018:
Thawing and Drying Operation(1) Wrap each material (2) Put the material intowith about 2 sheets of a commercially available
newspaper
futon compression bag
and vacuum it[3] Dry Cleaning

Focus on adherence development
Make sure the material is dry to
the inside

Air-dryablematerial(pages open or
surface dry)(3) Leave it overnight,
open, check thecondition, and classify
Material with highwater content(water soaks throughto the touch)

Store the materials temporarily
after completion

Work process at Hiroshima Prefectural Archives during the 2018 torrential rains in WesternJapan (Amano et al., 2019)

Next, they removed the frozen materials from the plastic bags andwrapped each item with absorbent paper (newspaper).
Putting the materials into pouches, they observed the progress in deaeration. After about 1 to 2 days, the frozen materials returned to room temperature. Confirming that the paper absorbed the moisture, they took the materials out of the pouches, replaced the paper, and degassed them again.
45

Repeating the process several times to separate the adhered materials
from one another, they finally dried them with air.
In this case, they could perform such a work process because they had ample
space at the archive and could use freezers, and many workers helped them withthe work. Depending on the location, it may be challenging to follow this process
as the power supply and pouches may not be available. For example, we can prevent dehydration without pouches by wrapping the materials in absorbent paper,
laying them on a flat surface, and placing something on top. The principle is thesame, and selecting a method that does not damage the materials is crucial.
3.2. Purpose of Cleaning

Cleaning is necessary to make it possible to temporarily store the materials
after drying. We have two options: dry cleaning (done in a dry condition) and wet
cleaning (done with water). The purpose of cleaning is to remove any spoilage
from the materials, but the extent of the treatment is an important issue. Since
most paper materials are documents, the process includes separating the adheredmaterials to prevent them from sticking to one another.
If wetting causes the adhesion, we can separate them by carefully making a
gap in the sticking area with a spatula or tweezers [Fig. 6: Material adhered bywater damage (sample)]. This process needs care and time: never run the risk of
breakage, and try to open from a different part. The opening can be highly challenging if mud or mould causes the adhesion. It is a good idea to stop the work,
document the current situation, pack the mouldy or dirty material to prevent itfrom scattering and focus on temporary storage to complete the emergency measures. In this case, it is desirable to remember that the first aid is only temporary
and to proceed with arrangements for the repair plan.
Depending on the damage, the dried materials may still have mud, mould, orother contaminants [Fig. 7: Material adhered by mould]. Therefore, it is necessary to remove mould spores on the surface by removing the mould with a clothor paper dampened with ethanol. We can remove mud stains so that the process
does not damage the materials, but dry cleaning has a limited effect. Moreover,brushing can run the risk of scattering. Therefore, during the dry cleaning stage,
opening up adherence is better than struggling to remove all the stains. Health46

Chapter 3 Rescuing Paper Materials

Fig. 6

Part 2

Fig. 7

hazard measures are necessary for this work: wear industrial masks with highdust-proof performance and high particle collection efficiency to prevent inhalation of mould and other contaminants. In Japan, DS2 masks meet the National
Inspection Standards set by the Ministry of Health, Labor and Welfare, as do N95
masks American standards and FFFP2 masks European standards, respectively.
Even if most of the work is adherence separation, mould and contaminants
scatter to some extent, so sufficient ventilation is necessary. Install air purifiers tokeep the work environment clean.
The first aid measures for paper materials aim to grasp the overall conditionof the materials; completely separate the adherence caused by water damage;and prevent odour, mould, and stain spreading for temporary storage. As forcible
attempts may result in large-scale damage, if even simple repair afterwards seems
impossible, adherence separation should be temporarily suspended. Sometimes,
wet cleaning may also be effective as an emergency measure to remove contaminants and odours. Usually, however, water-based cleaning requires the disman47

tling of the materials. In this case, too, it is a prerequisite to have the technology
and equipment to handle the materials after cleaning. Depending on the damage,the dried materials may still have mud, mould, or other contaminants. In rescuing
documents, we tend to focus on bringing the textual information to a readable
state as quickly as possible. However, from a long-term perspective, it is effective
for the preservation and inheritance of the materials to proceed in a step-by-stepand systematic manner.

Conclusion
Paper materials remain in vast quantities throughout Japan, and when rescued,
they are damaged, and the items come in large quantities. They are vulnerable
to water and breakage and require an extremely rapid response from the rescue
to the drying. Many practical reports are available, including those on familiar
materials (refer to them for specific techniques and information). However, it isimportant to note that the work process should be simple and that the first aid
should have specific goals. Thus, it will be essential to keep the following basic
objectives in mind: (1) dry the materials to get out of the immediate crisis, (2)open the materials to get an overview, and (3) manage the materials to proceed
toward a full-scale response. See the work mentioned in the reference for specificand simple ideas and methods in this process (YAMAGUCHI, 2022).

References
AMANO Masashi, YOSHIKAWA Keita, KATO Akie, NISHIMUKAI Kosuke, andSHIMOMUKAI Yuko. “Nishinihongou de suisonhigai wo uketa monjoshiryo kansoho
no kento [Drying Methods for Water-Damaged Documents in Heavy Rains in WesternJapan]”. Poster presentation at Japan Society for the Conservation of Cultural Property
41st Conference, 2019.
MASUDA Katsuhiko. “Suigai wo uketa tosho monjono shinkutoketsukanso [Report on
Vacuum-Freeze Drying of Books of Japanese Handmade-Paper]”, in: Hozonkagaku[Conservation Science], 31, 1992.
National Institutes for Cultural Heritage founded the Cultural Heritage Disaster Risk
Management Center (ed). Fuyukabito karano jintai no bogo ni kansuru manyuaru [Manual48

Chapter 3 Rescuing Paper Materials

for Human Protection against Floating Mould]. https://chdrm.nich.go.jp/facility/2022/03/
post-49.html (last visited 25 Dec 2023)
NISHIMUKAI Kosuke and SHIMOMUKAI Yuko. “Hiroshima kenritsu monjokan niokeru'Heisei 30 nen 7 gatsu gou' hisaibunsho no resukyu to hozenkatsudo [Rescue andPreservation of Materials Damaged by July 2018 Heavy Rains at Hiroshima Prefectural
YAMAGUCHI Satoshi. “kamiseichiikishiryo wo nokosu gijutsu [Technologies for
Preserving Paper-Based Local Materials]”, in: AMANO Masashi and GOTO Makoto(eds). Chiikirekishibunka keisho gaidobukku [Guidebook for Inheritance of Local
Historical Materials]. Bungaku Report, 2022.

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Part 2

Archives]”, in: Bulletin of Hiroshima Prefectural Archives, 15, 2020.