Mountboard Standards in the UK

["Stephen Todd" <Stephen.Todd@btinternet.com>]

>From Stephen Todd (list moderator)

The following is the text of a document
circulated to attendees of 3 symposia
organised by me in the UK in 1998.

I organised it at the request of the makers
of Bainbridge mountboard, for whom I work
as a consultant. However, I must emphasise
that the membership of the meeting
consisted of many other manufacturers and
was chaired by a leading and senior member of
the UK's Fine Art Trade Guild. The makers of
Bainbridge board have funded this programme
in order to bring clarity to descriptions
of mountboard in the UK.

I have posted it to the group for your input.
US members, be aware that in the UK, Museum (cotton
furnish) and Conservation (wood pulp) are considered
as separate materials, and are not always seen as
interchangeable.

Having declared my commercial `interest' I should
also say that I am a member of the Institute of
Paper Conservation (IPC) and not the Fine Art Trade Guild.

Here is the text. Unfortunately for technical reasons
I cannot include the references or tests, mail me if you need
them.

Stephen.
PS: I apologise in advance if the formatting of the text is
poor.
Standardised descriptions for conservation & museum quality
mountboard.

There are at present no UK standards for the description of
mounting boards used for backing or, with an aperture cut out of
the board, the framing or partially covering materials falling
under the overall description of cultural property. This is
paper borne art, prints, maps, photographs, and other items that
lend themselves to be stored or displayed using mountboard in
this way. Because of the value - intrinsic, historical or
monetary that may be placed on the materials that are framed
diverse terms have been used to draw user attention to the
various qualities of board.

This proposal is aimed at are:

1. Museums.
2. Conservators.
3. Framers of pictures or other cultural properties.
4. Manufacturers, and converters of the board.
5. Distributors of boards to users.

The types or grades of mountboard that are generally recognised
are:

a) Museum board - historically composed of cotton fibres.
Sometimes described as `rag' board.
b) Conservation board - boards made from `high alpha cellulose
wood pulp', and by implication of a performance, similar to, but
not as high as, museum board.
c) Standard board - boards used for similar purposes to the
above, but with less or no implied protection of the materials
with which it comes into contact.

The chief element of concern to users of these materials, and
other materials used in conjunction with them such as adhesives,
tapes and glass, is that their use does:

1. Not create damage or deterioration of the cultural item by
its use.
2. Not exacerbate or accelerate any existing damage.
3. Perhaps provide extra protection by containing materials or
chemicals that are known to negate or reduce harmful elements
that may already exist, or may occur in the display or storage
of the item -chemical buffers etc.

A principal focus of most users in this field is acidity and its
effect on cultural items, or the acidity of the item itself,
acid hydrolysis and other interactions with airborne
contaminants. A major cause of the embrittlement or
discoloration of the board or the item to be framed, is a
naturally occurring substance in wood fibres called lignin. A
complex polymer, the chief noncarbohydrate constituent of wood,
that binds to cellulose fibres and hardens and strengthens the
cell walls of plants, lignin is the `glue' that holds the fibres
together in plant materials. It is not currently possible to
make a viable mountboard made of wood pulp that is totally
lignin free, but it can be minimised in content and rendered
less harmful by processing, and by the subsequent addition of
chemicals to neutralise its effect.

Thus terms used to describe the quality and fitness for use of
mount boards over the years are:

Acid free.

Lignin free.

Wood free

Refined pulp

100% Cotton.

Neutral pH.

Museum quality.

Conservation quality.

Standard quality.

The problems associated with these descriptions are that they
have been used without definition or qualification and have now
become a subject of confusion rather than clarification.

In February 1998, a symposium was organised in the United
Kingdom by a manufacturer of mount boards, which was comprised
of a balance of the interested bodies. The were conservators,
picture framers, converters of mountboard and a trade
association, The Fine Art Trade Guild (FATG) and also the
Institute of Paper Conservation (IPC). A second symposium was
held in September 1998, during which time its composition had
changed to include more converters and distributors and more
conservators. The most recent event in October had a similar
composition to the second meeting.

Note: See http://www.users.globalnet.co.uk/~todnet/ for
information on these discussions in detail.

What follows is the first draft of the conclusions that were
reached. This draft will be distributed as follows:

1. To attendees of the meetings for correction and additions.
2. Repeat of the above with corrections.
3. Publication.
4. Implementation.

There is a facility to finalise all the foregoing at the Royal
Horticultural Society Hall, London, UK on June 27/28 1999.
Therefore it is requested that responses be received as quickly
as possible.
Apologies are offered for the delay in distribution.

Please read the above and the definitions that follow and submit
comments back to the writer:


Stephen Todd

Tel: 0161 486 0021
Fax: 0161 485 1221
Stephen.Todd@btinternet.com
http://www.users.globalnet.co.uk/~todnet/
http://www.btinternet.com/~todd.advertising/index.htm

6 Ack Lane West
Cheadle Hulme
Stockport
UK SK 8 7EL

This document was prepared in MS Word 97 SR2 and where emailed
as an embedded document was done so as a rich text format
document. It will also be posted on the web site:
http://www.btinternet.com/~todd.advertising/index.htm


Section 1
1. Museum Board
1.1. It should be made from 100% cotton fibre.
1.2. It must not contain post consumer waste.i
1.3. Pre consumer waste must be of a known, identifiable and
identical quality.
1.4. The use of the term `Rag' should be discontinued as it
implies the inclusion of recycled waste material.
1.5. The use of the term `acid free' should be dropped from the
description of museum mount board.
1.6. Unbuffered museum board will have a pH of 6.5 to 7.5.ii
When used for mounting for display of photographic prints it
should pass the Photographic Acidity Test. (PAT)iii See 8.1.
1.7. Buffered museum board will have a pH in the range of 8.0
 0.5.iv When used for mounting for display of photographic
prints it should pass the Photographic Acidity Test. (PAT)v See
8.1.
1.8. Only neutral or alkaline sizing which is stable must be
used. vi



Section 2
2	Conservation Board
2.1 Should have a chemically purified wood pulp core, facing and
backing paper, with an alpha cellulose content of no less than
84% vii (that is 87% ( 3%)
2.2 It must not contain post consumer waste.
2.3	The lignin content should be less than 0.65%, equivalent to
a Kappa number of 5 or less. viii
2.4	Pre consumer waste should be of a known, identifiable and
identical quality.
2.5 The use of the term acid free should be dropped from
describing Conservation mount board, as it is indefinable
without reference to pH.

Section 3 (Common Specifications)
3	Fillers and Alkaline Reserves for Museum and Conservation
Board
3.1	Alkaline reservesix may act as fillersx. Alkaline reserves
should constitute a minimum of 2% and a maximum of 5% of the
total volume by weight.
3.2	Activated charcoal, calcium and magnesium carbonate and
zeolites are allowable fillers.
3.3	Only neutral or alkaline sizing which is stable must be
used.xi

4	Colours
4.1	Only pigments should be used in order that there is no
bleeding.
4.2	Only pigments should be used in order that there is light
fastness.xii
5	Lamination Adhesive
5.1 Only neutral or alkaline adhesives that contain no external
plasticisers and are stable should be used.xiii

6	Packaging and Markings
6.1	Packaging and its markings should clearly indicate the
content quality - Museum, Conservation etc., and a batch number.
7	Thickness
7.1	The thickness should be described in microns.
8	Photographs
8.1	See 1.6, 1.7 above. This is a specification for mountboard
descriptions and not for usage. However, most authorities
recommend unbuffered museum board for use with photographs. Some
authorities state that a buffered board would have merit for
photos that are brittle and mounted onto old mounts of an acid
pH. It should be noted that photographs can be printed onto a
base of almost any composition, especially with the advent of
digital photography and high quality colour printers.
Glossary

Cultural Property: used to encompass the wide variety of items
that come into contact with mountboard.

Conservators: workers in the field of preservation of cultural
materials.

Matboard: the North American word for mountboard.

Rag: an historical word. Paper and board can be made from cotton
materials that are recycled.

Pre Consumer Waste: waste materials produced by the manufacturer
of the mountboard that is thus identifiable as being of suitable
quality.

Post Consumer Waste: all recycled materials suitable for the
manufacture of paper or board and thus not identifiable as being
of suitable quality.

Light Fast: the resistance of paper or board and cultural
property to fading in light.

Acid Free: containing no acid.  More commonly of a neutral or
alkaline pH, which could describe materials that have been
de-acidified by chemical purification, or materials that were
not acidic initially.

Museum Quality: a UK description of an all cotton board.
Elsewhere it is used interchangeably with Conservation Quality.

Conservation Quality: in the UK a description of woodpulp board
that has hitherto implied a degree of protect by nature of its
chemical purification, without a definition of what content of
lignin, buffers etc. ensures such a description.

Standard Quality: mountboard that may or may not contain
elements of conservation quality.

Bleed(ing): diffusion or dispersion of the dyes used for
mountboard to other areas of the same board, or cultural
materials, or materials associated with the picture frame etc.
Tests
i TAPPI T401 (Graff "C" stain fibre analysis -IPST)
ii TAPPI T509
iii PAT ISO 10214-1991 or ANSI/APM IT9.16-1993
iv TAPPI T509
v PAT ISO 10214-1991 or ANSI/APM IT9.16-1993
vi TAPPI T509
vii TAPPI T401 (Graff "C" stain fibre analysis -IPST)
viii TAPPI T236
ix ASTM D4988 - 89
x ASTM D4988
xi TAPPI T509
xii BSI 1006: 1997 or (ISO) R105 (B01 or B02) Blue Wool Fading
Standards
xiii TAPPI T509
1




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