Hand-Reading

Eugénie Falise, Laurence Leroy
Peer-Reviewed
Hand-Reading
The Conservation of Braille-Embossed Books
The restoration of Elements d'arithmetique—a handbook printed
in relief for blind students in 1840—offers us the opportunity to
contemplate about the treatment and the preservation of brailleembossed books: How to strengthen them in order to allow hand
reading.
We have tested various strengthening agents: wheat starch paste
(CTS) with Japanese paper (Kuranai, kozo fibres: Stouls Conservation), Tylose® MH 300 P (Tylose ® MH 300 P methyl hydro xyéthyl
cellulose: CTS), Plextol B500© (aqueous dispersal of a copolymer
based on ethyl acrylate and methyl metacrylate: Kremer pigments)
and Paraloid B72© (Paraloid B72, acrylic resin: CTS) diluted in
acetone. The samples of braille-embossed paper consolidated by
these agents were placed under a rubbing simulator, which we
had previously developed.
The samples were then sent to the technical centre for paper in
Grenoble (CTP, Grenoble, France <www.webctp.com>) in order to
measure the depth of braille dots on rubbed-samples, and to compare them with non-rubbed samples.
Our findings reveal that although Plextol B500© provided
very good results, Tylose® MH 300 P used with both water and
ethanol was more suitable, since the other products impacted too
much on the height and the shape of the dots. Furthermore,
Tylose® MH 300 P proved to be more reversible.
2011: 1). In his manuscripts he recounts his life and work at the
institution. Leca-Mattei wrote his notes by embossing the paper
by hand. The content of his text did not exist in any other version. The dots of these manuscripts were almost erased when
Valérie Choisel transposed them from embossed to ink-printed
texts. It allowed us, then, to retrieve great deal of information
about life at the Blinds Institutio, which otherwise would have
been lost.
As far as braille preservation is concerned, a large range of
actions is possible. One could work on improving the storage
conditions in order to protect the relief, by using anti-shock
boxes. The environmental conditions themselves must also be
thought through, as paper preservation depends greatly on the
surrounding relative humidity. Furthermore, conservation treatments may diminish or slow down the damage of the relief.
Introduction
Elements d’arithmetique is a mathematics handbook written
by Louis Braille in 1840. This book (Fig 1)—intended for blind
students—was printed with alphabet letters in relief. It was,
indeed, the way books for blinds were made before the spread of
braille as we know it nowadays.
During the restoration of the artefact we could observe that
the relief—distinctive feature of the object—was very damaged.
Paper was worn, letters were getting detached, and some were
even missing (Fig 2). These kind of deteriorations could also be
observed on more recent books, printed in braille—meaning,
with embossed dots. This issue affects and concerns libraries and
organisations in charge of receiving and circulating books dedicated for the blinds. Even if most of these books were initially
devised ‘in black’—that is to say for sighted persons, what about
the ones which do not exist in an alternative version? It is a
whole heritage doomed to vanish if the text cannot be transposed before it is totally flattened.
The manuscripts of Thomas Leca-Mattei, dated 1883, are
such an example. Leca-Mattei was a teacher at the Blinds Institution [1], and was responsible for the adapting the braille
system of writing to the four mathematical operations (Roy
1
Eléments d’arithmétiques, by Louis Braille, 1840.
Journal of PaperConservation Vol. 15 (2014), No. 4
Background
There is no perfect answer to the relief-preservation issue.
Several conservators addressed the three-dimensional aspect of
artworks on paper and its preservation. Some, used blocks or
moulds (Erhardt and Padfield 1982: 11-12), others preferre Paraloid B72® or cyclododecane (Hendry 2001: 5-7). The formers
imply a long-treatment duration, which is problematic in the
2
Technique of embossing (detail).
7
Eugénie Falise, Laurence Leroy
field of book conservation. The latters require noxious solvents,
harmful for paper and non-reversible. So can we strengthen
embossed paper with more commonly used materials such as
Japanese paper, adhered with starch or cellulosic paste? The aim
of the following experiment is to answer this question.
Experimental
We created some braille embossed paper samples, on which different strengthening products were applied. These samples were
then placed under a rubbing simulator. The depth of the embossed points was measured before and after the product application, and after the rubbing.
Procedure
A mould given by the printing house of Valentin Haüy Association [2] was used to create the samples. It was devised of two PVC
plates on which the braille alphabet was embossed. These plates
were strictly identical and interlocked one into the other. The
paper, wet and squeezed into them, has been pressed and took
the embossed shape.
In order to simulate the repetition of a movement, we developed a machine using a turntable (Fig 3). We replaced its
diamond by a pad and jammed its arm so that it would always
remain on its initial path. We also weighted the arm so that the
pad would not leap over the embossed areas. The table itself was
covered with cardboard, on which samples were fastened. Some
preliminary tests have been conducted in order to determine the
optimal pad, the tests duration, the weight and location of the
ballast.
Eventually, we decided to use a pad with a diameter of
20 mm made out of rigid plastic covered by felt. Samples were
exposed to a 120 minutes test, which means that the arm passed
3
The rubbing machine.
on the samples 5,520 times. The arm of the turntable carried a
ballast of 30 g located at its end.
The exact dots depth on the braille-embossed samples has
been controlled by the Technical Centre of Paper [3] in Grenoble (France) who has elaborated a machine able to measure
braille dots depth: the Braille Dot Tester [4]. The machine, created by the CTP and commercialised by its branch Techpap, enables the measurement of the dots of a braille-embossed text.
It is much quicker and much more precise than a microscope
(Fig 4). For each sample the Braille Dot Tester gives a curve representing the dots of the sample, with their maximal depth
(line 3), their average depth (line 2) and their width (line 3). The
Braille Dot Tester was, at first, dedicated to medicine packaging.
Indeed, the height of braille dots is normalised [5] and must be
controlled. The braille Dot Tester is a compact machine that can
be used in production sites, during the production itself or at the
reception of products as a quality control tool. There is no direct
contact with the sample. This tool has been commercialised in
2009, upon the Louis Braille bicentennial.
A 4 cm text-line has been embossed on the samples. The rubbing machine carried a 20 mm pad and could not uniformly
cover bigger samples. We measured the braille dots depth after
the samples had been exposed to the rubbing machine. Then we
compared the results to the depth of un-rubbed dots, using our
reference samples. The smaller the difference was, the stronger
the paper was. Besides, we compared the depth of dots on consolidated paper and un-consolidated paper; and we observed a
loss of relief due to the application of the adhesive.
Choosing the Samples
The variable parameters were the type of paper and the strengthening product, which was applied directly onto the support or
through Japanese paper. We chose two different papers. The first
one was Scandia 2000© (coated paper: Perche), a paper used in
braille industrial embossing. Its basis weight was 100 g.m-2,
and it was coated. It was a wood-free paper pulp, which resists
well to ageing and is certified Nordic Swan [6]. We possessed only
a few samples of this paper. Hence, in order to try several techniques of strengthening, we preferred to use a common blotting
paper, with no additives in the pulp [7], un-coated and having
also a basis weight of 100 g.m-2.
4
8
Information
provided by
the CTP for
each sample
(example).
Journal of PaperConservation Vol. 15 (2014), No. 4
Hand-Reading
We decided to test two kinds of consolidation: one consisted
of applying a adhesive through Japanese paper, the other of
using adhesive alone, letting it soak into the paper. For application with Japanese paper we chose wheat starch adhesive (wheat
starch adhesive in powder form: CTS), hydroxypropylcellulose
(Klucel G©: CTS) diluted in ethanol, methyl hydroxyethyl cellulose (Tylose® MH 300 P: CTS) diluted first in water and then in
water combined with ethanol. Indeed, ethanol was less damaging
on paper relief than water. These adhesives are those most frequently used in paper conservation studios. The different adhesives were tested on each type of paper by adhering the Japanese
paper on the verso and for some samples also on the recto. The
purpose was to determine what solution was the best one.
Wheat starch was prepared at 20% w/v in water, Klucel G©
was prepared at 5% w/v in ethanol. Tylose® MH 300 P was made
at 5% w/v in water and at 5% w/v in a mixing of 70% water and
30% ethanol. Using Japanese paper offered better reversibility
than direct application of adhesive onto paper, and it limited the
amount of humidity provided by the adhesive itself. Furthermore, the amount of adhesive was better controlled, which was
essential for creating standard, and comparable, samples. The
Japanese paper had to be thin enough to fit closely the dots
shape, but strong enough to enhance a real protection. The
9 g.m-2 Japanese paper is the one which complied the best.
Indeed, previous tests had shown that 6 g.m-2 was too thin and
a thicker paper prevented the readability of the dots.
The adhesives we had tested without Japanese paper were
Paraloid B72© (Paraloid B72, acrylic resin: CTS)—so we could
ascertain whether it was efficient or not, and Plextol B500©
(aqueous dispersal of a copolymer based on ethyl acrylate and
methyl metacrylate: Kremer pigments) diluted in water—an
adhesive, which is, both strong and very flexible. We did not find
a precise concentration for Paraloid B72© in literature. Thus, we
decided to use it diluted in acetone, in a mixture of 10% w/v,
resulting in an efficient but also sufficiently fluid solution allowing for an easy application. The same applied to Plextol B500©,
which we had used diluted at 80% in water. It is obvious that
these products, once applied on paper, were not—or, only very
slightly—reversible.
Procedure Validation
Strips of strengthening Japanese paper were pasted onto
Melinex©, using the brush in two directions until the Japanese
paper was saturated. Obviously we always tried to reproduce the
same gesture in order to restrict the error factor. The soaked
paper was then dropped off on the sample paper with a dry brush
so that no more adhesive was added (Fleygnac et al. 2012: 141).
When the Japanese paper was pasted on onto the verso, we
worked on a foam board in order to avoid dots flattening.
To validate the procedure a repetition test has been conducted. We weighed 10 samples of same-sized braille-embossed
papers. They were weighed before and after being pasted on with
a 1 x 1.4 cm Japanese paper strip of 40 g.m-2. The results confirmed that this process lead to a small margin of error. Thus,
we can say that the samples have always the same quantity of
adhesive in general.
Journal of PaperConservation Vol. 15 (2014), No. 4
Japanese paper was useful for both limiting and controlling
the input of adhesive. In regard to Paraloid B72© or Plextol
B500©, it was more relevant to apply it directly on the support,
so that the liquid could soak the paper and strengthen it from
the inside.
However, to control the amount of product added, we
checked the weight of the paper samples before and after receiving a layer of adhesive.
Results and Discussion
The information provided by the Technical Centre of Paper is
gathered in the following figures. Tab 1 gives the loss of relief
according to the strengthening agent and Tab 2 compares them.
First of all Klucel G© has been suppressed from the tests
very quickly. Indeed it was notable without any further measures that its adhesion strength was not sufficient to provide a
decent answer to braille-dots conservation issue.
Paraloid B 72
Although the loss of depth was important—nearly 30%, the
paper was substantially more resistant when it was protected by
Paraloid B72©. Indeed, the rubbing test did not affect significantly the relief once it was strengthened.
In addition, photographic images ascertain that the dot
shape was very well preserved, which enhance the readability of
dots with the fingers (Fig 5). Eventually Paraloid B72© in acetone diminished the relief but preserved it very well against erosion.
Wheat Starch Paste 20%
Similar to Paraloid B72©, starch paste may be a satisfying solution since there was no significant loss of depth after the rubbing
test. Although, the adhesive itself still affected the relief and a
loss of almost 25% of relief could be observed when the starch
paste was applied. This loss of depth was close to the one observed with Paraloid B72©.
However, pictures show that the outline of dots were less
precise because of the extra layer provided by Japanese paper
and adhesive (Fig 6). The surface was irregular and creases were
noticeable. As a result, dots were more difficult to feel.
When the Japanese paper was pasted onto the verso of the
sample, the relief was less damaged. Unfortunately the reinforcement was also less efficient. Indeed it was very difficult to
push the strengthening paper deep into the dots without damaging them. As a consequence, Japanese paper was not pasted
on to the bottom of the dot.
To conclude, although the observed results are encouraging,
consolidation with starch paste and Japanese paper is not the
ideal solution, especially for books available in libraries reading
rooms. It would rather be a suitable solution for books exhibited in museums or destined to be read only occasionally.
Tylose® MH 300 P
The adhesive, applied through Japanese paper, reduced the relief
of the braille dots by around 40%. This was far too much for
Tylose® MH 300 P to be considered a practical use. The phenom9
Eugénie Falise, Laurence Leroy
Tab 1 Loss of depth according to the strengthening agents.
Strengthening agent
when the product is applied
Loss of relief
after rubbing
Is the loss
significant?
Loss if relief
Is the loss
significant?
1 Japanese paper+ wheat starch paste (applied on the recto)
25%
Yes
5.4%
No
2 Japanese paper+ wheat starch paste (applied on the verso)
6.3%
No
8%
No
3 Japanese Paper + Tylose® MH 300 P in water
40%
Yes
10%
Yes
4 Japanese Paper + Tylose® MH 300 P in water + ethanol
12%
Yes
1.4%
No
5 Paraloid B 72 (applied on the recto)
27%
Yes
5%
No
6 Plextol B500 (applied on the recto)
9%
No
0.3%
No
7 Plextol B500 (applied on the verso)
0.6%
No
5%
No
350
300
250
Original dots depth (µm)
Dots depth after application of the
glue (µm)
200
Dots depth after rubbing (µm)
Tab 2
150
100
1
2
3
4
5
6
enon could be explained by the fact that Tylose is a wetting
agent. Thus it lessens the surface tension of water, its solvent.
This adhesive is, as a consequence, a better wetting agent than
starch adhesive. Moreover, it did not provide an efficient mechanical strengthening since we have noticed a loss of relief during
the rubbing test.
For that reason, Tylose was also tested with ethanol in addition to water. The relief was then better preserved, when the
strengthening was applied, resulting in a loss of relief of only
5
10
Macro
picture
of brailleembosseddots
strengthened with
Paraloid
B72©.
7
Comparison
of the diverse strengthening agents
numbered
1 to 7 in
accordance
with Tab 1.
12.5%. Moreover the strengthening was efficient, and dots depth
was not significantly affected after the rubbing test. Yet this
adhesive preserved the outlines of the dots better than starch
adhesive, through the same Japanese paper. Indeed this can be
explained by this adhesive’s improved flexibility.
In conclusion, Tylose® MH 300 P and Japanese paper could
be an appropriate answer to the relief preservation of braille dots,
when ethanol is added to the adhesive.
6
Macro
picture
of brailleembosseddots
strengthened with
starch paste.
Journal of PaperConservation Vol. 15 (2014), No. 4
Hand-Reading
Plextol B 500
Plextol B 500 provided excellent results. Applied onto the recto
of samples it lead to a loss of only 9% of the relief, and protected
very well the paper against rubbing. Indeed the depth of dots was
almost strictly the same before and after being rubbed. Applied
onto the verso there was nearly no loss of relief when the adhesive was applied and neither when the sample was tested
under the rubbing machine.
The problem with this product is its non-reversibility and the
glossy aspect it gives to the paper. Although this is less notable
when strengthening is done from the verso. The glossy aspect
may not be important for blind people but is essential if the
restored book is meant to be exhibited.
Conclusion
In order to reinforce the paper of braille-embossed books, the
most suitable solution would be, according to this experiment,
Japanese paper adhered with Tylose prepared with 30% ethanol
and 70% water affording better reversibility. This solution is preferred to Plextol B 500, even though the latter provides better
results, on the face of it.
Let us add that any intervention on braille dots affects both
the height and the shape of the dots, and thus their readability.
In future, it would be interesting to consider other solutions,
such as cross linkers or Wet Strength agents, to study the idea of
reinforcement not only on paper surface but also into the paper
structure itself.
Acknowledgements
We are very thankful to the Valentin Haüy Association (AVH, Paris,
France) for the loan of Elements of arithmetics, and for the trust
Mrs Roy, the curator, gave us. We appreciated greatly the help of
the Technical Centre of Paper (CTP, Grenoble, France) without
whom these researches could not have been conducted. Finally
we thank André Le Prat, Pr. Pepe and Pr. Roux for their guidance
and their help provided within the last year.
Endnote
[1] Nowadays this school is called the National Institute of Young
Blinds (INJA: Institut National des Jeunes Aveugles) and is
located on 56 Boulevard des Invalides, Paris, France.
[2] Organisation for blinds assistance. It has its own museum, printing house and library, among other services. Elements of Arithmetics by Louis Braille belongs to its collection. AVH, 5 rue Duroc, 75343 Paris Cedex 07, France.
[3] This institution is known as CTP. It is this acronym we will use
in the following text.
[4] In accordance with the EN 15823 norm that specifies the demands
about braille marking on medicine packagings.
[5] In that case the recommended height is 200 µm.
[6] Label that certify a product is devised according to a process
respectful of the environmental protection issues.
[7] The supplier did not give us the exact composition of the paper
pulp.
Journal of PaperConservation Vol. 15 (2014), No. 4
References
Canadian Institute of Conservation, 2011. Symposium 2011
report <www.cci-icc.gc.ca/symposium/2011/Poster%20-%
20Sirven%20et%20al.%20-%20French.pdf>, viewed 4th April
2013.
Centre Technique du Papier (2009): Papier communicant, papier
intelligent. In: Retrospective. Rapport Annuel du CTP, pp 13.
Erhardt, D., and Padfield, T. (1982): Method for making molds
from embossed paper. In: 8th IIC-Cg annual conference, pp 11-12.
Fleygnac, O. , Martin, A. , and Rouchon, V. (2012): Le vernissage
des globes: le cas du globe manuscrit du musée Buffon (Montbard). In Support Tracé, Vol 12, pp 135-142.
Hendry, H. (2001): Yves Gaucher’s Homage to Webern N°1:
a multidimensional treatment. In: The Book and Paper Group
Annual 20(2001). Dallas: AIC, pp 5-7.
Roy, N. (2011): Débraillage. In: Le Louis Braille. Novembre 2011.
Website of Centre technique du Papier (2010), Braille Dot Tester
< www.techpap.com/data/fckeditor/file/Braille%20dot%20
counter%20v012_F_M_001.pdf>, viewed 1st July 2014.
Website of the City of Quebec, Universal accessibility guide
<www.irdpq.qc.ca/communication/publications/guide_
accessibilite/acces_Fiche6.pdf>, viewed 4th April 2013.
Weygand, Z. (2003): Vivre sans voir, les aveugles dans la société
française du moyen-âge au siècle de Louis Braille. PhD thesis.
Paris: Graphis.
Suppliers
Géant des Beaux-arts, 166 rue de la roquette, 75011 Paris, France,
+33 1 46 59 43 00, www.geant-beaux-arts.fr (blotting paper).
CTS, 26 passage Thiéré, 75011 Paris France, + 33-1-4355-6563,
www.ctseurope.com (Starch paste, Tylose® MH 300 P, Klucel G,
Paraloid B72).
Kremer Pigmente, 247 West 29th street, New York NY 10001
USA, 212.219-2394, www.kremer-pigmente.com (Plextol B500).
Perche, 41 avenue du Général Leclerc, 92350 Le plessis-Robinson,
France, Tel +33-140-831600, www.perchepapiers.fr (Scandia
2000 paper).
German Title and Abstract
Tastlesen: Die Restaurierung von Braillebüchern
Die Restaurierung der Elements d’arithmetique – einem 1840
gedruckten Handbuch zur Unterstützung sehbehinderter Studenten – bietet uns die Möglichkeit, sich mit erhaltenden Maßnahmen von Reliefschriftbüchern auseinanderzusetzen: Wie kann
man sie festigen, um weiterhin ein Tastlesen zu ermöglichen?
Wir haben unterschiedliche Festigungsmittel getestet: Weizenstärkekleister (CTS) mit Japanpapier (Kuranai, Kozo Fasern:
Stouls Conservation), Tylose® MH 300 P (Methyl Hydroxyethyl
Cellulose: CTS), Plextol B500© (wässrige Dispersion eines
Copolymers basierend auf Ethylacrylat und Methylmethacrylat:
Kremer Pigmente) und Paraloid B72© (Acrylharz: CTS) gelöst in
Aceton. Proben des mit diesen Festigungsmitteln konsolidierten
Reliefschrift-Papiers wurden unter einen vorher entwickelten
Abrieb-Simulator gelegt. Die Proben wurden danach in das Technische Zentrum für Papier in Grenoble (CTP, Grenoble, Frankreich) gesendet, um die Tiefe der Braillepunkte auf den beriebenen Proben zu messen und diese mit unberiebenen Proben
zu vergleichen. Unsere Untersuchungsergebnisse zeigen, dass
obwohl Plextol B500© sehr gute Resultate erzielte, Tylose® MH
300 P in Wasser sowie Ethanol besser geeignet war, da die anderen Produkte Höhe und Form der Punkte zu sehr veränderten.
Außerdem zeigte Tylose® MH 300 P eine bessere Reversibilität.
11
Eugénie Falise, Laurence Leroy
Authors
Eugénie Falise is a French paper curator. She has a Master diploma
in heritage restoration- conservation, minor paper conservation, at
Condé School (Paris) in 2013. She holds a research scholarship,
meaning a 6th year in Condé School, under the guidance of
Mr. André Le Prat. She is now working in Liège, Belgium, as a
freelance curator in partnership with the Artbee Conservation
Studio (12 rue d’Harscamp 4000 Liège, Belgium).
Eugénie Falise, Rue Sohet 29, BE-4000 Liège, Belgium,
Tel +32-497-235975, [email protected],
www.drpaper-conservation.com
Laurence Leroy is a research scientist is the ‘board and paper
normalization, performances and quality’ scientific and technical
unit of the TECHNICAL CENTRE OF PAPER (Centre Technique
du Papier, known as CTP, Grenoble, France). Holding a diploma
in the French School of Paper sciences and graphic industries
(called today PAGORA) in 1995 and a PhD in the National Institute of Polytechnics of Grenoble in 2002, she is head of research
projects about paper physics, printability and transformation. She
works above all on the field of boards, hygienic papers and unwoven. She participated at the development of the CTP Braille
Sensor and is member of the working group of ‘normalisation
of braille marking on pharmaceutical packaging’.
Laurence Leroy, Domaine Universitaire, CS-90251,
38044 Grenoble Cedex 09, France, Tel +33-476-154079,
[email protected]
ADVERTISEM ENT
12
Journal of PaperConservation Vol. 15 (2014), No. 4