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Articles by Chris A. Paschke, CPF GCF
"Hinge
Basics"
November 2004
Preservation
framing is designed to maintain and preserve the original value of the art being
framed by using noninvasive materials and techniques. Whether original charcoal, pencil drawing,
signed etching, limited edition, watercolor, photograph, or digital art, they
should all be mounted using traditional conservation hinging techniques with
Japanese papers and cooked starch paste, or preservation mounting
alternatives.
Preservation
mounting methods are those that allow the mounted artwork to be removed from
the mounting having it return to its original unmounted state. This removal is known as being a reversible
process. Accepted alternatives include
commercial and hand constructed corner pockets, edge strips, and prepasted
hinges, let's explore.
ARCHIVAL OVERVIEW
The
word "archival" has been bantered about in the framing industry, like
acid free, for years. Archival is a word
used to describe materials that are safe to use when preparing an item for long
term storage and preservation. In
framing, it refers to the relative permanence or longevity of a given material
and its ability to remain stable over time.
Hence, we assume that when manufacturers use the term archival in their
advertising and naming of products they are being true to the above
description.
Only
true archival hinging materials should be used when preservation framing. That includes mounting strips of 100% cotton
rag paper; Mylar and polypropylene edge strips and pocket corners; dry Japanese
prepasted nonsticky tapes; rice and wheat starches in powder form; prepared
commercial powers that activate with water but do not need cooking; Japanese
hinging papers of assorted weights; burnishing bones, blotters and drying
weights.
There
are many manufacturers and distributors for hinging materials, while only a few
will be mentioned here. Check all
sources when shopping for preservation materials.
PRESSURE-SENSITIVE
ADHESIVES
Conservation
techniques involve starch pastes, but there are also pressure-sensitive and
gummed materials that may be used in the preservation package. A pressure-sensitive adhesive is a permanently
tacky substance that bonds to an untreated surface at room temperature, by only
the application of slight pressure.
Pressure-sensitive materials for preservation hinging include corners,
strips, and tapes and may also called self-adhesive tapes, P-S tapes, or PSA
adhesives.
P-S
adhesives are in a constant active phase, making them less stable than starch,
or even gummed materials. They bond to
25% of their full capability with only thumb pressure and should be burnished
to be thoroughly activated. Even though
acrylic based p-s adhesives are considered reasonably stable, slipping can
occur if the hinged item is heavy, or if temperatures and humidity levels are
high.
Since
acrylic p-s bonds may become more aggressive over time and the plasticizers and
tackifiers can migrate into RC photos, acrylic paintings, and assorted
synthetic materials which can be a problem long term. Chemical reactions can occur between the
adhesive and plastics based art images developing cold-flow (cold-creep, or
cold-crawl) which allows the adhesive to aggressively melt around fibers of the
artwork making removal very difficult.
P-S IN PRESERVATION
Pressure-sensitive
adhesives used in conjunction with preservation mounting techniques should
never come in direct contact with fine art as hinges. ArtSaver® Archival Mounting Strips; Lineco
Archival Mounting Corners, Mylar Photo Corners, and Polypropylene Framers
Corners; and See-Thru polyester Mounting
Strips make up a few of the available pressure-sensitive archival edge strips
and corner pockets acceptable as preservation applications (photo 1). Since these p-s
adhesives are inert they will not harm a conservation package and since they
are not in direct contact with the art they remain safe to use.
photo 1
Clockwise
from upper left: ArtSaver Archival Mounting Strips;
Lineco
Archival Mounting Corners, Mylar Photo Corners, and
Polypropylene
Framers Corners; See-Thru polyester Mounting Strips
and bone burnishers
make up a few of the available pressure-sensitive
edge strips and corner pockets.
Though
p-s paper tapes are not suggested for preservation mounting, they might be used
for easily replaceable images, short term display, or artwork not considered
valuable, including: open edition reproductions, poster art, some photographs
and items sensitive to water such as inkjet digitals. Pressure-sensitive tissue tape is the closest
thing to traditional cooked starch and torn tissue hinges without moisture,
while still being a ready-to-use, acid-free, neutral p-s tape. Assorted weights and tapes allow for
selecting the right strength for any application (photo 2). Linen tapes, regardless of pressure-sensitive or gummed, should never be
used to hinge any art. They are perfect
for long side book hinges (flange hinge) that attach the window mat to the
backing board.
photo 2
Both
P-S and gummed linen hinging tapes may be used for
attaching window mats to the backing boards, while
P-S and
gummed paper tapes are designed for the hinging of
art.
Assorted
weights and types of tapes allow for selecting the
right strength for the art. Lineco, Neschen,
University Products,
and NielsonBainbridge
included in photo.
GUMMED OR WATER
ACTIVATED ADHESIVES
Water
activated or dry gummed and tape adhesives are made from animal, vegetable, or
mineral sources. Of those, only
vegetable starch pastes should be used in preservation hinging. Gummed tapes are preferred by conservators to
pressure-sensitive tapes in framing because of their easier removal with water,
and their long term hold regardless of temperature and humidity
fluctuations.
VEGETABLE STARCHES
Vegetable-based
starches free of gluten are the adhesive of choice for preservation hinging,
such as rice and wheat starch. These are
available in numerous versions from ready to cook powder form to precoated
Japanese paper strips. Nori, is
a precooked, prepackaged, ready-to-use, wheat starch containing no
preservatives (photo 3). There is a precooked version called Zen
Instant Wheat Starch which is are water soluble, freeze dried crystals which
mix into a non-staining, reversible, pH neutral paste.
photo 3
There
are commercial gummed and pre-pasted tapes; dry rice
and wheat starches ready to cook; and powders
that require
no cooking. Assorted rice papers allow for the correct
fiber
strength to allow the hinges to remain the weakest
link in the
hinging process. Weights, blotters, and burnishing
bones are
all frequently used items when traditionally hinging
artwork.
Lineco,
Nori, and NielsonBainbridge
included in photo.
There
are also starch saturated, predried, water soluble tapes or strips such as
Insta-Hinges® and Hayaku® Japanese Hinging Paper. Both are neutral pH, reversible products that
only need to be moistened to activate their adhesive. The best way to saturate a dry tape is to
allow moisture to wick up into the hinge from a soaked blotter beneath rather
than to brush water onto it. The abrasive
action of moist brushing serves to remove some of the adhesive thus weakening
the potential bond.
TRADITIONAL HINGING
MATERIALS
Japanese
hinging uses only noninvasive, reversible starch adhesive in conjunction with a
lightweight Japanese rice papers. Hinges
need to be light but strong, and since rice papers are made from long fibers
this allows for a strips to be wet separated and feathered when creating
them. This feathering helps prevent a
ridge from developing where the hinge meets the art after pasting.
The
hinge should always be the weakest link in the hinging process which is why
there are a series of available papers used in hinging and an assortment of
hinging techniques. Pick your hinging
papers accordingly. The best hinging
papers are handmade of 100% kozo fibers in variable weights including: mulberry
(heavyweight), kizukishi (medium weight), toso tengujo
and kozogami tsuru
(lightweight). It is the duty of the
hinge to tear before the art tears if the frame were to fall from the wall.
CORNER POCKETS AND
FOLDED STRAP CORNERS
Corner
pockets are a way of conservation mounting where there is no adhesive of any
kind coming in contact with the artwork.
As already established they may be commercially purchased or they may be
simply constructed of rice paper strips and mounted using starch pastes (photo 4). The photo sampler shows two corners that have
been constructed with mulberry paper.
The upper left version is a small ½" x 2" piece of torn paper
that was moistened with water for wet pulled fiber separation. Then fold the strip to form a ½" x
1" triangle corner that is glued to the 4 ply backing board with starch
paste (diagram 1). This is the same basic construction as a
Lineco Self-Folding Corner made of Mylar polyester with p-s adhesive seen in
photo 1.
photo 4
Corner
pockets may be commercially manufactured
of Mylar or polypropylene, or handmade of rice paper
strips.
Clockwise
from upper left is a folded mulberry corner pocket;
Lineco
Mylar Photo Corner; ½" handmade mulberry folded strip;
and polypropylene cut away pocket.
The
lower right corner is an open strap of mulberry paper torn 3/8" x
2-1/2" and folded as in diagram
2. A strap corner supports a greater
portion of the art corner for better support on larger images, and less
likeliness for damage. This type of
hinge can also be integrated into the actual frame design as when floating the
art (photo 5).
photo 5
This
piece originally framed in 1985 shows modified
strap corners that hold the rice paper
calligraphy floated.
The
straps are then held beneath the edges of the
inner mat rather than glued.
OPEN
STRAP CORNER
The small original Chinese calligraphy
(5" x 12"), framed in 1985, shows modified strap corners that hold
the rice paper calligraphy floated in the center of the window mats. The straps were not folded back creating
pockets, but rather are held beneath the edges of the inner bottom mat then
glued in place. Because this is a very
lightweight piece of thin rice paper the unfolded straps have held and the art
has not shifted, even after two cross country moves. But for art with any weight these supports
should be folded strap corners.
The
problem with using heavier commercial corner pockets made of polypropylene is
their inherent strength that could dent or tear the corners of the art if it
fell. Mylar corners are thinner and more
likely to split than some of the heavier plastic corners, perhaps making them a
better choice. Edge strips could also
hold to aggressively rather than giving way, which could cause the art to bunch
at their side contact points.
BASIC PENDANT HINGE
The
most basic and frequently used preservation hinge is the pendant hinge. Small feathered strips of rice paper have been moistened and
wet separated leaving the long fibers pulled at all edges. Lay the hinge on a scrap of 4 ply rag and
brush starch glue along the bottom 1/4" (one quarter inch) of the
hinge. Let it set a moment for the
initial shine of the paste to dry away then align along the top back (verso) side
of the art.
Burnish
the wet hinge with a clean brush or burnishing bone to smooth, press out air
and feather edges of the hinge. Place a
small 3x3" piece of spun polyester (Pelon) over the moist hinge, then a
3x3" dry blotter followed by a weight.
The Pelon prevents the blotter from sticking to the hinge while
drying. It should be allowed to dry
about an hour depending on humidity conditions.
After
the hinge has dried, the remaining hinge portion is then adhered, weighed and
dried as above to the 4 ply backing board.
A small unglued portion of the original pendant hinge allows the art to
hang freely and the Japanese paper hinge would be allowed to tear if the frame
were to fall to the floor (photo 6). Pendant hinges are used when a window mat
will be covering and additionally supporting the hinged art around all sides.
photo 6
The
small 5X7" original is hinged with large mulberry paper strips
attached with cooked starch paste to the upper
1/8" (one eighth inch)
of the back, then reinforced with a cross piece for
demonstration purposes.
This
is considered a reinforced Pendent Hinge.
Hinge
placement across the top of the art varies depending on the size and weight of
the image, but the outermost hinges should begin a little more than one width
(not length) of the hinge from the edge of the art. Additional hinges might be needed at 12-15"
intervals.
T-HINGE
A
T-hinge is a reinforced pendant hinge.
These are the strongest hinges which give the most support to the
art. The base of the T-hinge comes in
contact with the back side of the top edge of the art image like the pendant,
and then a second piece is applied horizontally across the face of the first
piece (diagram 3).
The
horizontal T portion of the hinge may be crossed farther away from the art than
shown in the photo to allow for greater flexibility of the art during expansion
and contraction if that seems to be a serious a consideration. Remember that
allowing for hinge and art flexibility will never work if the mats and filler
boards are compressed too tightly into the closed frame.
When
creating T-hinges any pressure sensitive paper or linen tapes could technically
be used. They are there to reinforce the
original pendant portion, never come in contact with the art and would be
discarded with the backing board if ever separated from the fine art.
END
Copyright
© 2004 Chris A. Paschke
For more articles on mounting basics
look under the mounting section in
Articles by Subject.
Additional information on all types
of mounting is found in
The Mounting and Laminating
Handbook, Second Edition, 2002, and
The Mounting And
Laminating Handbook, Third Edition, 2008.
Creative Mounting, Wrapping, And
Laminating, 2000
will teach you everything you need to
know
about getting the most from your dry mount equipment and
materials as an innovative frame designer.
All books are available from Designs
Ink Publishing through this website.
Chris A Paschke, CPF GCF
Designs Ink
Designs Ink Publishing
785 Tucker Road, Suite G-183
Tehachapi, CA 93561
661.821.2188