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Remoistenable Tissue Preparation and its Practical Aspects
by Andrea Pataki
Abstract: Remoistenable tissues are used to repair local tears and loss areas on moisture-sensitive
objects, including those carrying copper green-containing pigments or iron gall ink. Gelatin, isinglass,
cellulose ethers, starch ether and synthetic adhesives such as Aquazol
®
and Paraloid™ B72 were
found to be suitable adhesives to prepare the remoistenable light-weight tissue repair paper. These
remoistenable tissues are activated either with water, water/solvents or solely solvents. The choice for
a suitable adhesive is influenced by its ability to form an adhesive film, by its concentration, by the
flexibility of the tissue-adhesive preparation, by its transparency and by the adhesive swelling ability
that enables its activation. Minimum and maximum adhesive concentrations, a range of light-weight
tissues and activation methods are presented. A swelling test for adhesive films is discussed that allows
evaluation of the activation process. The Berlin tissue was favored as tissue support, and a mixture of
wheat starch paste and methylcellulose or gelatin were found to be suitable adhesives. Funori and
JunFunori
®
did not evidence sufficient activation for this use.
Zusammenfassung/résumé at end of article
received: 09.09.2008 revised: 01.02.2009
1. Introduction
Micro-tears and small losses due to corrosive pigments and writing media such as
copper-based green pigments and iron gall ink represent a common damage in paper
conservation. Locally restricted damaged areas are found, for example, with fine art
drawings carrying iron gall ink (van Gulik 1997); they exist in Indian miniature
paintings or Arabic manuscripts that are often surrounded by borders drawn with
green copper containing pigments. The corrosive action of these pigments and the
complex structure of illuminated manuscripts often prohibit aqueous treatments
because of undesirable side effects because they may encourage the hydrolytic
degradation of the cellulosic support. Therefore, the stabilization of tears and losses,
which is usually done by locally adhering a tissue to the weakened area, makes it
necessary to limit the use of water required for the adhesion process. To repair or to
stabilize water-sensitive objects, thin tissue precoated with an adhesive film that only
needs to be activated with water, water/ethanol mixtures or organic solvents before
it is applied constitutes a solution to this treatment problem.
Restaurator, 2009, pp. 51 – 69
Printed in Germany
.
All rights reserved
Copyright © Saur 2009
ISSN 0034-5806
Restaurator 30: 51 – 69 © 2009 Saur, Munich etc.
10.1515/rest.004
51
2. Remoistenable tissue
Baker (1990) presented remoistenable lining with an aqueous and non-aqueous
adhesive for supporting fragile water-sensitive paper objects. She suggested a mixture
of wheat starch paste and methylcellulose (MC). Brückle and Wagner (both 1996)
altered the ratio between wheat starch paste and MC. Quandt et al. (2002) also
suggested the mixture of wheat starch paste and MC for reinforcing areas of corroded
copper green-containing pigments in illuminated manuscripts. Biggs (1997) repaired
losses in iron gall ink-damaged paper objects with Klucel
®
G-coated gossamer tissues
that were activated with ethanol and therefore could be used non-aqueously. Titus
(2004, see also contribution in this issue) reinforced 19th-century copy press
documents suffering from iron gall ink corrosion with a remoistenable tissue
equipped with gelatin that was activated with a water/ethanol mixture. Arabic
papers showing copper green pigment corrosion were treated by Meyer (2005) and
Rose (2006) with a mixture of wheat starch paste and MC to reinforce the micro
tears. Curled albumin prints were lined with remoistenable tissue (Brückle 1996).
The overview shows that several adhesive systems have been in use for treating
different damages of water-sensitive objects.
On the basis of previous work by the author on adhesives used for consolidation of
friable paint films, the following adhesives were investigated for their suitability for
remoistenable tissues: gelatin and isinglass (protein-based adhesives) (Pataki 2005
and 2006), methylcellulose and hydroxypropylcellulose, i.e. Klucel
®
G, (cellulose
ethers), Kollotex
®
1250 (starch ether), the mixture of wheat starch paste and
methylcellulose, Paraloid™ B72 and Aquazol
®
200 (synthetic polymers), Funori and
JunFunori
®
(polysachharide-protein mixtures). Funori and JunFunori
®
consist of
ca. 88 to 95% of polysaccharaides and small fractions of protein. The fraction of
protein is relevant for its yellow colour (Pataki 2006).
Kollotex
®
1250 is not yet known well as adhesive in conservation, but it shows
interesting features (Güttler 2008). It is used as a refining substance in the textile
industry. The ether side group is hydroxyethylether, which realizes a pH of 7 and a
non-ionic character which is compatible with cellulosic substrates. It is dispersible in
water and easy to prepare.
Aquazol
®
was introduced as an adhesive for paintings and objects conservation
(Wolbers et al. 1998) and lately was used as a consolidant for oil paintings on tracing
paper (Gindroz 2006). It can be dissolved in several different organic solvents as well
as water which make it a promising adhesive for remoistenable tissue, making it
comparable with Klucel
®
.
Remoistenable Tissue Preparation and its Practical Aspects
Restaurator 30: 51 – 69 © 2009 Saur, Munich etc.
52
For preparing a remoistenable tissue, a liquid adhesive is brushed on a smooth
polyester film support with a smooth brush, and the light-weight tissue is placed on
the moist adhesive film. Due to the liquid adhesive film and the low grammage of the
paper, the tissue is wetted immediately and no more brushing is advisable. Any
brushing incorporates the danger of damageing the fibres and to dislocate them. If
the tissue is not brushed down, the tissue is rather floating on the adhesive film . This
helps to create an adhesive film with a light-weight tissue on top. This set-up is
allowed dry. If a micro-structured and matte water-repellent foil is used, the adhesive
film take up the structured surface and the tissue-adhesive sandwich becomes rather
matte in appearance. Micro-structured and matte foils are found, for example, as
transparent polyethylene letter envelopes. For storage the remoistenable tissue can
be kept on the polyester film.
The shape and size of the prefabricated dry remoistenable tissue can be cut on the
support film, which should be slightly larger than the loss area. This piece of repair is
then peeled away fro m the polyester film. The activation is done with water, water/
organic solvent-mixtures (e.g. water:ethanol 30:70 to 50:50) or solely organic
solvents using a fine brush. The activation process can also be performed in a Gore-
Tex
®
sandwich, which can be set up with water or water/solvent impregnated
blotters. Then, the tissue is placed on the object and the area is placed under light
pressure. In the case of the Gore-Tex
®
sandwich, it is advisable to mark both the
position of the tissue within the sandwich as well as its coated side; otherwise, it is
hard to find it again.
The amount of moisture needed to activate the adhesive film is rather smal l,
which is one reason why conservators use this repair technique in the case of objects
suffering from iron gall ink corrosion (Titus 2004, see also contribution in this issue)
or copper pigment corrosion (Quandt 2002, Rose 2006). For proper function of the
tissue, it is important that a coherent and sufficient thick adhesive layer is prepared.
This can be achieved if the tissue is let floated on the wet adhesive layer during
preparation. The content of moisture can be even reduced by using water/solvent
systems.
The remoistenable tissue realizes a rather light adhesion power between the
activated adhesive and the object. The repair paper should be weaker than the
damaged area, so that in the case the area endures stress, the remoistenable tissue
should break rather than the object itself.
Andrea Pataki
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53
2.1 Tissue types and their relevant characteristics
A local stabilisation treatment should not attract the viewer’s eye, because the micro-
tear or the loss may be situated in the middle of a central design area of the object.
Therefore, the tissue should be as visually unobtrusive as possible, most suitably
consisting of gossamer tissue (Fig. 1). This paper was introduced into conservation by
Frank Mowery from the Folger Shakespear Library, Washington (Biggs 1997). It
consists of kozo (30 %) and mitsumata fibres (70 %) and weighs only ca. 2 –4 g/m
2
.
Bansa and Ishii (1999) further reduced the tissue weight to ca. 1.7 g/m
2
using a
technique similar to leaf-casting that involves applying discrete fiber layers to
weakened paper objects. Machine-made Japanese tissue paper is also available as RK
0 and RK 00 with thicknesses of 5 and 3.6 g/m
2
(Paper Nao, Japan) and the Berlin
tissue made by Gangolf Ulbricht, Berlin, has a grammage of 2 g/m
2
. These light-
weight tissues are suitable to be coated with adhesives to be activated by
remoistening. The heavier paper is mechanically stronger and is therefore more
suitable in cases where more support is needed.
Figure 2 presents RK0, RK00, Gossamer tissue and Berlin tissue. They are
arranged from the heaviest to the lightest tissue and placed on a modern printing
paper on which black bars are printed. The fibres of the porous RK0 and RK00 papers
Fig. 1 Remoistenable tissue, adhesive film on the lower side, which is slightly glossy.
Remoistenable Tissue Preparation and its Practical Aspects
Restaurator 30: 51 – 69 © 2009 Saur, Munich etc.
54
are clearly visible. The Gossamer tissue is extremely fine and less porous. The Berlin
tissue shows a fine, even fibre network. Gossamer tissue and the Berlin tissue allow
more continuous contact area with the object due to their finer structure compared
with the RK papers. The latter will have less contacting points with the object.
Gossamer tissue, however, is not available commercially.
In this study, the Berlin tissue was favored as it has an exceptionally even structure
and is very translucent which makes it unobtrusive in conservation applications on
original objects. It is commercially available and its handling is easy.
3. Adhesive concentration, film flexibility and activation solvent
The adhesive should be able to create a smooth, coherent film on the tissue. The film-
forming ability is dependent to a great extent on the concentration of the adhesive
preparation. Suitable minimum and maximum workable concentrations (given in %
and w/v) of a range of adhesives on polyester films such as Melinex
®
, determined in
trial applications, are given in Table 1. All adhesives are prepared in water except of
Klucel G
®
(dissolved in ethanol) and Paraloid™ B72 (dissoled in ethyl acetate). The
methylcellulose (MC)/starch mixture involves equal parts of 3% MC 4000 (w/v)
Fig. 2 RK0, RK00, Gossamer tissue and Berlin tissue (from left to right) over modern office paper. The
fibres of RK 0 and RK 00 are positioned rather singular in comparison to the Gossamer tissue and the
Berlin tissue. These fibres are dense and finely distributed.
Andrea Pataki
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55
and 2,5 % wheat starch paste (w/v) according to the recipe of Quandt (2002). All
adhesives were applied on the Berlin tissue. The table also includes an empirical
evaluation of the flexibility of the dried adhesive-coated tissue. The latter
characteristic is expressed in symbols that express degrees of flexibility from slight
(+) to very (++++); this property was tested manually by bending and bowing the
samples with two hands for four to five times and feeling coated tissue samples. In the
very right column of Table 1, suitable activation solvents are given. The order of
adhesives is choosen according to chemical groups of the different polymers and does
not impose a preference.
Dependent on the type of adhesive, workable concentrations range from 0.5 to
25%. The reason for these great differences is the adhesive-specific grade of viscosity.
MC 400, for example, has a lower viscosity, i.e. 400, in comparison to MC 4000,
which has a viscosity of 4000, expressed in mPa·s. To prepare a functioning adhesive
film, a higher concentration is needed when using the MC 400 in comparison to MC
4000. This correlation of viscosity and workable adhesive film needs to be
determined empirically for each adhesive quality, because the rheological character-
istics of the different types of adhesive differ to a great extent [2]. It should be noted
that Funori and JunFunori
®
are unsuitable as adhesives for remoistenable tissue.
Although a film can be created on the tissue, no tacking power will be realized after
activating the adhesive film.
The grammage of the tissue does not influence the flexibility of the remoistenable
tissue as long as a light-weight tissue is used. The adhesive film alone rather defines
the flexibility and therefore the adaptation to the object. Gelatin and isinglass coated
remoistenable tissues will create rather less flexible repair-papers in comparison to
Paraloid™ B72, Klucel
®
G and Aquazol
®
500 which realize very soft, elastic repair-
papers. Starch-based adhesives (MC/starch, Kollotex
®
1250) and MC develop
flexible films. These statements are derived from empirical experiments. The
flexibility of the remoistenable tissue need to be taken into consideration related to
the size of the repair area. The larger the repair paper need to be, the more flexible it
should be. The remoistenable tissue should never be stronger and firmer than the
original support.
Paraloid™ B72 is activated with ethanol or ethyl acetate. All other adhesives can
be activated with water. To reduce the amount of water required for this process, a
mixture of water and an organic solvent, for example ethanol, is used. The maximum
concentration of ethanol is ca. 50% to realize a satisfactory activation process.
Klucel
®
G and Aquazol
®
can be dissolved either in water or organic solvents. Klucel
®
is the brand name of hydroxypropylcellulose which can be dissolved in either water
or an organic solvent such as ethanol because of its specific side group. Aquazol
®
is a
Remoistenable Tissue Preparation and its Practical Aspects
Restaurator 30: 51 – 69 © 2009 Saur, Munich etc.
56
synthetic polymer, Poly(2-ethyl-2-oxazoline), which can be dissolved in a range of
organic solvents such as alcohols, esters, aromatics as well as water (Wolbers et
al. 1998). That means that these two types of adhesive can be dissolved in water and
activated in alcohol or the other way round. To maintain a low moisture
environment during treatment, a water/ethanol mixture or ethanol are advisable
for adhesive activation, even if the adhesive film as initially prepared in water.
Figure 3 shows four tissues coated with gelatin (3 %, w/v). The translucency is
increased, because the adhesive was activated and adhered to a substrate. Compared
Table 1: Minimum and maximum concentrations of adhesives for coating tissue paper, empirically
determined flexibility property (+ to ++++) of the prepared tissues, and solvents suitable for their
activation. In the case of the MC /starch paste mixture, the concentration was not altered.
adhesive %
minimum
flexi-
bility
%
maximum
flexi-
bility
activation
solvent
protein gelatin 3
(warm)
++ 8
(warm)
+ H
2
O
H
2
O / ethanol
isin-glass 3
(warm)
++ 8
(warm)
+ H
2
O
H
2
O / ethanol
cellulose ether,
starch ether
MC 400 1 +++ 4 ++ H
2
O
H
2
O / ethanol
MC 4000 0.5 +++ 2 ++ H
2
O
H
2
O / ethanol
Klucel
®
G2++++ 5 ++++ H
2
O
H
2
O / ethanol
ethanol
Kollotex
®
1250
(starch ether)
10 +++ 25 +++ H
2
O
H
2
O / ethanol
MC 4000/
starch paste
2.7 ++ 2.7 ++ H
2
O
synthetic
polymer
Aquazol
®
500 5 ++++ 10 ++++ H
2
O
H
2
O / ethanol
ethanol
Paraloid™ B72 10 ++++ 20 ++++ ethyl acetate,
ethanol
poly-saccha-
ride/protein
Funori 0.1 1.0 no activation
JunFunori
®
0.1 0.5 no activation
Andrea Pataki
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57
to gelatin-coated tissue, starch-based adhesives, such as the MC/wheat starch paste
mixture and the starch ether are slightly more opaque and therefore reduce the
translucency of the remoistenable tissue repair to some extent.
The activation was evaluated by moistening the coated remoistenable tissue with
a fine brush and by placein g them on a modern printing paper. This empirically
testing leaded to the following observations.
The remoistenable tissue realizes only moderate to low adhesion power on the
paper substrate. Therefore, it is also easily removed from the object. It needs to be
humidified locally or dampened with a fine brush to make detachment possible.
Dependent on the kind of adhesive, water, water/solvent mixtures or organic
solvents can be used for activation of the adhesive.
Klucel
®
G-coated tissues have low adhesive strength and might not realize a good
adhesion between the mending paper and the object. Therefore, the mixture of
wheat starch paste and methylcellulose, gelatin or isinglass are still favoured by
conservators. The adhesive strength is higher base d upon empirical findings and the
Fig. 3 RK0, RK00, Gossamer tissue and Belin tissue (from left to right) are coated with gelatin (3%, w/
v) and adhered to modern office paper. The translucency is enhanced in comaprison to the uncoated
fibres in Figure 2.
Remoistenable Tissue Preparation and its Practical Aspects
Restaurator 30: 51 – 69 © 2009 Saur, Munich etc.
58
amount of water needed for activation can be reduced to a minimum by activation
with a water/solvent mixture. Gelatin is particularly interesting because of its
capability to fix iron(III) ions (Kolbe 2004). This behaviour might be of advantage for
local repairs of iron gall corrosion on paper.
Aquazol
®
200 creates higher adhesion power than Klucel
®
according to the
empirical tests. A negative characteristic of Aquazol
®
is its tackiness at room
temperature, which might be a problem for its use in conservation practice.
3.1 Testing adhesive swelling
The swelling ability of polymers in different solvents were presented by Down 1999
to gain an idea about the removability of varnishes on oil paintings. Phenix (2002)
tested the swelling of non-aqueous binding media that had been mixed with
pigments to observe the swelling under the microscope and predict the removability
of binding media or varnishes on paintings. The amount of swelling was measured by
comparing the digital images before and after the swelling process. The size of the
surfaces are also calculated and compared. The work of Down and Phenix served as a
basis for developing a low-tech test method to evaluate the swelling ability of a
selection of the above-described adhesives. The swellability of the adhesive film is
relevant for the activation of the remoistenable tissues. It gives an idea if a dry
adhesive film does take up moisture at all and to what extent which is a prerequisite
of any adhesion at all. However, so far the correlation between swelling ability and
strength of an adhesion could not be established.
In this test, 30 ml of 1 % adhesive solutions (except of Aquazol
®
, 60 ml) were
poured in Ø 8,5 cm PS-petri dishes and allowed to dry for a few days. The adhesive
films were then adhered to a Whatman Filter Paper #1 using limited amount of
water. The films were fixed between two object glass slides. In an upright position,
photographs were taken (50 x) to document the thickness of the dry adhesive film.
Before swelling, one glass slide was removed and the filter paper then was soaked in
tap water. The sample was placed close to the upper edge of the object glass slide.
Surplus water was wicked up with dry filter paper. At the bottom of the object glass
slides, two bull-dog clips are placed to hold the object glass slides plus sample in an
upright position (Fig. 4). After ca. two minutes, digital photographs are taken again of
the swollen adhesive film in this upright position to document the thickness of the
now swollen adhesive. Trial applications demonstrated that adhesive swelling
reaches a maximum after a few minutes and then remains stable for several minutes.
The visible reduction in thickness starts only much later during the course of the
drying process which is prolonged because the wetted Whatman Filter Paper
Andrea Pataki
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59
provides a water reservoir. Fig. 5 shows the dry and the swollen gelatin adhesive
film; Fig. 6 shows the dry and swollen Funori film. Gelatin swells ca. 300 % in
comparison to Funori which increases its thickness by ca. 866 % from its dry state
(see Table 2). The % swelling was calculated with the help of the Photoshop
®
grid and
ruler function. The thickness of the object glass slide (1 mm) served as an internal
standard in the calcuation. The method was reproducible with only minor
deviations. However, it has to be kept in mind that this low-tech test method that can
only give a general idea of the swelling ability of adhesive films.
All tested adhesives absorb water and therefore are suitable for the activation
process within the application of remoistenable tissues. Funori and JunFunori
®
can
not be activated with water and are therefore not suitable as adhesives. All other
adhesives can be used as coatings for light-weight tissues.
Fig. 4 Set-up for the swelling-test. The sample on the filter paper is attached by adhesion to the upright
standing glass slide held by two bulldog clips.
Remoistenable Tissue Preparation and its Practical Aspects
Restaurator 30: 51 – 69 © 2009 Saur, Munich etc.
60
4. Treatment example
A 17th-century manuscript (Hauptstaatsarchiv Stuttgart, Inv. Nr. H128, Band 312)
was disbound and resewn. The manuscript contained 102 folios written with iron
gall ink. Twentyeight inscribed areas were damaged due to iron gall ink corrosion,
Fig. 5 An adhesive film of gelatin on filter paper in the
dry state (left) and after swelling in tap water (right).
Gelatin swells ca. 300%.
Fig. 6 An adhesive film of Funori on filter paper in the
dry state (left) and after swelling in tap water (right).
Funori swells ca. 866%.
Andrea Pataki
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61
showing micro losses, and therefore required stabilization (Fig. 7). Because the
damages were limited to isolated areas throughout the manuscript and apart from
that the iron gall ink was not endangering the support paper, an aqueous treatment
was not taken into consideration. The damage areas were stabilized locally with
Table 2: The thickness of dry and swollen adhesive films in mm and the percentage of swelling
adhesive dry film mm wet film mm % swelling
gelatin 0,05 0,14 300%
isinglass 0,05 0,14 300%
MC 400 0,05 0,14 300%
Klucel
®
G 0,07 0,12 166%
Kollotex
®
1250 0,05 0,1 200%
Aquazol
®
200 0,1 0,12 125%
Funori 0,07 0,6 866%
JunFunori
®
0,05 0,52 1100%
Fig. 7 Manuscript page (detail) showing a small loss in area inscribed with iron gall ink.
Hauptstaatsarchiv Stuttgart, H128, Band 312, fol. 62v.
Remoistenable Tissue Preparation and its Practical Aspects
Restaurator 30: 51 – 69 © 2009 Saur, Munich etc.
62
remoistenable tissues. The MC/starch paste adhesive mixture (ratio 1:1, Quandt
2002) on Berlin tissue was used. The coated tissue was activated with water in a
Gore-Tex
®
sandwich for 5 minutes and set down on the weak areas ensuring good
contact by immediately applying slight pressure with a finger. The time frame for
adhering the activated tissue is small because the adhesive remains tacky only for a
few seconds. Because the amount of water introduced is very minimal, minimizing
also potential side effects of this treatment, it was important to choose an adhesive
that would realize sufficient adhesion between the coated tissue and the object.
Therefore, the MC/wheat starch paste mixture was chosen. The Berlin tissue was
chosen as repair paper because the weak areas were very small and surrounded by
stable undamaged paper (Fig. 8).
5. Conclusi on
Adhesives must show some swelling capacity to be activated with water, water/
ethanol mixtures or organic solvents, which makes them suitable for being used in
remoistenable tissue applications. Using a low-tech method to record the swelling
Fig. 8 Manuscript page (detail) showing loss area after stabilization with remoistenable tissue.
Treatment method: Berlin tissue coated with a MC/wheat starch paste mixture and activated in a
Gore-Tex
®
sandwich. Hauptstaatsarchiv Stuttgart, H128, Band 312, fol. 62v.
Andrea Pataki
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63
behaviour of wetted adhesive films, it was shown that they swell to different extents
(125% to 1100%). Remoistenable tissue preparation also requires that a film can be
created on a smooth support such as Melinex
®
. Conservators use remoistenable
tissue with gelatin, a mixture of MC/wheat starch paste or Klucel
®
G. Good results
can also be obtained by using isinglass, MC, Kollotex
®
1250 or Aquazol
®
as adhesive
layers. If an object allows for the use of organic solvents, Paraloid™ B72 can also be
used. The tested adhesives differ in their flexibility, the concentration required, their
activation solvents and finally their adhesion power.
At concentrations between 3 and 5%, proteinaceous adhesives are less flexible but
show a higher adhesion power in comparison to Klucel
®
G, Paraloid™ B72 and
Aquazol
®
. These create very soft films and have less adhesion power. MC-based
adhesives and the starch ether create flexible films. Funori and JunFunori
®
proved
unsuitable for being used for remoistenable tissues. All adhesives except Paraloid™ B72
can be activated with water or water/solvent systems. The concentration of ethanol
should not exceed more than 50% in relation to water when using gelatin, isinglass, the
MC/starch paste mixture, MC or starch ether to enable a sufficient activation process.
Paraloid™ B72 can only be activated with organic solvents. Klucel
®
and Aquazol
®
can
be used in both aqueously and non-aqueously as they create real solutions with either
organic solvents or water. Although Aquazol
®
shows a higher adhesion power than
Klucel
®
G, it is slightly tacky at room temperature which detracts from its usefulness.
The tackiness of Aquazol
®
is critical and need further investigations. However, the wide
range of solvents to be dissolved is a great advantage.
If the humidity is reduced to a minimum, the MC/starch paste mixture and
gelatin show good working characteristics. The Berlin tissue is an excellent choice as
support because it is very fine and even. The treatment example demonstrates that
choosing these tissue preparation parameters, sufficient stabilization and visually
acceptable results can be achieved.
Acknowledgement
The author thanks Irene Brückle, Staatliche Akademie der Bildenden Künste
Stuttgart and Abigail Quandt, The Walters Art Museum, Baltimore, for fruitful
discussions and literature research. Thanks go to Ulrike Hähner, Universitätsbi-
bliothek Marburg, who invited the author for a lecture on the occasion of the final
colloquium of the DFG-project. Stephan Lohrengel carried out the case study and
gave practical hints on how to activate the remoistenable tissue. Eva Hummert
helped to further improve the preparation of the adhesive film sheet samples. Nancy
Turner, Karen Trentelman and Alan Phenix, all J. Paul Getty Museum, Los Angeles,
Remoistenable Tissue Preparation and its Practical Aspects
Restaurator 30: 51 – 69 © 2009 Saur, Munich etc.
64
were helpful discussants in the preparation of this paper during the author’s three-
month Museum Guest Scholarship there. The Landesstiftung Baden-Württemberg
has granted the author a post-doctoral project to carry out this work.
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Design Stuttgart 2006. http://bibliothek.fzk.de/zb/berichte/FZKA7168.pdf.
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method for measuring the in-plane swelling of unsupported paint films. Journal of
the American Institute of Conservation (JAIC) 41 (2002): 43 –60.
Quandt, A.: Remoistenable tissue for mending paper damaged by copper pigments.
Manuscript and Paper Conservation Department, The Walters Art Museum,
Baltimore, Handout prepared for the IIC meeting 2002 in Baltimore, USA, 2002.
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The Institute of Conservation, Edinburgh, 2006, Postprints. Ed. S. Jaques, London:
Institute of Conservation 2006, 79– 86.
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Diploma thesis, unpublished, Stuttgart: Staatliche Akademie der Bildenden Künste
2004.
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european workshop on iron gall ink corrosion, 16–17 June 1997, Rotterdam:
Museum Boijmans Van Beuningen Rotterdam and Instituut Collectie Nederland
Amsterdam, 1997: 47–50.
Wagner, S.: Remoistenable tissue part II: variations on a theme. The Book and Paper
Group Annual 15 (1996): 27 –28.
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conservation consolidant. In: Painted wood: history and conservation. Ed. V.
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514– 527.
Remoistenable Tissue Preparation and its Practical Aspects
Restaurator 30: 51 – 69 © 2009 Saur, Munich etc.
66
Materials and suppliers
“Berlin Tissue”, 2 g/m
2
, Mitsumata (Suruga), Kozo (Ibaragi), bastfibres from Japan:
Gangolf Ulbricht, Mariannenplatz 2, D-10997 Berlin, Germany.
RK 00 (3,6 g/m
2
, Mitsumata) and RK 0 (5 g/m
2
, Kozo): Anton Glaser, Theodor-
Heuss Straße 34A, D-70174 Stuttgart, Germany.
Isinglass, Funori, JunFunori
®
, Klucel
®
G, Aquazol
®
200, Paraloid™ B72: Kremer
Pigmente, Hauptstraße 41, 88317 Aichstetten /Allgäu, Germany.
Kollotex
®
1250, Avebe Business Unit Applications
Avebe-weg 1, NL-9607 PT Foxhol, Niederlande
Gelatin: VWR International (Merck nr. 1. 04078.1000), John-Deere- Straße 5, D-
76646 Bruchsal, Germany.
Methylcellulose (MC 400, MC 4000): Hercules GmbH/Aqualon Division, Paul-
Thomas-Straße 56, D-40599 Düsseldorf, Germany.
Polystyrol (PS)-Petridishes, Carl Roth GmbH, Schoemperlenstraße 1 –5,D-76185
Karlsruhe, Germany.
Appendix
[1] Viscosities in mPa·s are given for the following adhesives tested with a
Viscosimeter, Thermo Haake VT 500/501Zylinder MV 1 (it has to be kept in mind,
that viscosity can be tested with different viscosimeters which needs to be taken into
account when comparing test results from different instruments):
Gelatin: 30 mPa·s (Pataki 2006, 88)
Isinglass: 30 mPa·s (Pataki 2006, 88)
MC 400: 400 mPa·s (technical handbook of Methocel Cellulose Ethers by the Dow
Chemical Company, page 19).
MC 4000: 4000 mPa·s (technical handbook of Methocel Cellulose Ethers by the
Dow Chemical Company, page 19)
Klucel
®
G (in ethanol): 210 mPa·s (technical handout of Klucel, physical and
chemical properties by Hercules, page 16)
Andrea Pataki
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67
Kollotex
®
1250: 11 mPa·s (technical Handout by Avebe Ref.Nr. 119216/Version01,
24. Februar 1997)
Paraloid™ B72: 0,44 mPa·s (technical handout from Kremer Pigmente)
Zusammenfassung
Herstellung von feuchteaktivierbaren Tissues und deren Anwendung in der Praxis
Schließt sich eine wässrige Behandlung von Objekten aus, eignen sich remoistenable tissues für die
lokal begrenzte Fehlstellenergänzung. Vor allem bei Objekten, die mit Kupfergrün und Eisengallus
Tinte ausgestattet sind, erscheint diese Methode als sinnvoll. Für den Einsatz von remoistenable
tissues sind eine Reihe von Klebstoffen in Gebrauch, die als dünne Schichten auf feine Papiervliese
aufgebracht werden und mit Wasser, mit Wasser-Lösungsmittel Mischungen oder nur mit Lösungs-
mitteln befeuchtet bzw. aktiviert werden. Trotz des gut dokumentierten Einsatzes von remoistenable
tissues gibt es keine Richtlinien, nach denen die Auswahl eines geeigneten Klebstoffes begründet
wird. Als wichtige Kriterien werden die folgenden Eigenschaften aufgestellt: Die Konzentration, mit
denen Klebstofffilme erreicht werden, die Flexibilität des Klebstoff-Vlies-Verbundes, mögliche
Aktivierungslösungen und die Quellfähigkeit des Klebstofffilms. Die geringsten und höchsten
Klebstoffkonzentrationen für mögliche Klebstoffe sind erarbeitet und ein Quelltest, um die
Aktivierung des Klebstofffilms zu testen, ist entwickelt worden. Gelatine, Hausenblase, Cellulosee-
ther, Stärkeether, eine Mischung aus Weizenstärkekleister und Methylcellulose, Aquazol
®
und
Paraloid™ B72 werden beschrieben. Funori and JunFunori
®
können nicht aktiviert werden und
erscheinen daher für den Einsatz nicht geeignet. Das Berlin tissue wird als Träger dieser
Stabilisierungsmethode favorisiert, da es gut zu beschichten ist, manuell hergestellt und eine geringe
Grammatur aufweist. Als Klebstoffe eignen sich das Klebstoffgemisch und Gelatine, solange die
eingebrachte Feuchtigkeit für das Aktivieren gering gehalten wird.
Résumé
Préparation de tissu réhumectable et ses substances adhésives
Les „tissus de papier réhumectables“(tissus de papier susceptibles d’être réactivés à l’humidité) sont
utilisés pour réparer les dégradations et remplir les espaces détruits sur des objets sensibles à
l’humidité, y compris surtout ceux qui ont été endommagés par des pigments contenant du vert-de-
gris ou des encres ferro-galliques. La gélatine, l’ichtyocolle, les éthers de cellulose, l’éther d’amidon et
toute une série d’adhésifs synthétiques tels que l’Aquazol
®
et le Paraloid B 72 ont été utilisés et
considérés comme adéquats pour être utilisés dans la préparation du tissu de papier fin servant à
réparer les dégradations. Ces tissus réhumectables sont activés soit par l’eau seulement, soit par des
mélanges d’eau et d’alcool ou uniquement par des agents solvants. Les critères qui influencent le choix
de l’adhésif à utiliser sont définis en fonction de sa capacité à former un film adhésif, de sa
concentration, de la flexibilité du tissu adhésif, de sa transparence et de sa capacité de gonflement qui
Remoistenable Tissue Preparation and its Practical Aspects
Restaurator 30: 51 – 69 © 2009 Saur, Munich etc.
68
permet sa réactivation. Seront présentés les concentrations maximales et minimales des différents
adhésifs en question ainsi que toute une gamme de fins tissus et de méthodes d’activation. On discute
d’un test de gonflement pour les films adhésifs qui permet d’évaluer la méthode d’activation. On a
donné la préférence au tissu de Berlin comme support et comme adhésif on a considéré qu’un mélange
d’éther d’amidon de blé avec de la cellulose de méthyle ou la gélatine étaient les adhésifs les plus
appropriés. Funori et JunFunori
®
semblent ne pas développer suffisamment de force d’adhérence et ne
peuvent donc être retenus.
Author
Dr. Andrea Pataki is head of the conservation laboratory at the graduate conservation education
programme for conservation of works of art on paper, archive-and library material at the State Academy
of Art and Design Stuttgart, where she also obtained her diploma (1997) and her PhD (2006). In the
year 1998 she was an advanced fellow supported by the German Academic exchange program,
DAAD, at the Walters Art Museum, Baltimore. She currently conducts a two-year postdoctoral
research programme funded by the Landesstiftung Baden-Württemberg. In spring 2008, she was
invited as a Museum Guest Scholar at the J. Paul Getty Museum, Los Angeles.
Contact
Dr. Andrea Pataki
Head of the Conservation Laboratory
State Academy of Art and Design Stuttgart
Höhenstraße 16
D-70736 Fellbach
T: +49 711 66 46 38 14 (tel)
F: +49 711 58 64 53 (fax)
Mail: andrea.pataki@abk-stuttgart.de
Andrea Pataki
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69
