Acid
Free
Material with a pH of 7 or greater.
Archival Paper
Paper that is free of acid and lignin.
The paper may have neutral pH (6.5 to 7.5) or be buffered.
Adhesive
A material that causes two surfaces to adhere
to each other. Adhesives used in picture frames include pressure sensitive
tapes, cooked starch paste and polyvinyl
acetate.
Alpha Cellulose
The most pure of the three forms of cellulose,
the chief constituent of all plants. Alpha cellulose is characterized
by the longest polysaccharide chain. The strongest, most stable papers
are made from alpha cellulose fibers.
Anti-reflective
Glass
Glass that is treated, usually with a thin film
coating, to significantly reduce reflections without significantly
affecting the sharpness of a framed image or object behind the glass.
Barrier Material
A layer of material that is used in the framing
package to impede the migration of acid, especially between molding
and fillet and art. Aluminum foil with an acrylic
adhesive on one side and buffered, acid-free,
lignin-free paper on the other is most commonly
used.
Conservation
Framing art and objects with materials and methods
that provide a stable environment and minimize the deterioration of
the framed item. Synonymous with preservation.
Conservator
A person specially trained to restore an item
to as close to its original condition as possible. The amount of restoration
possible depends upon the item's current condition. A conservator
usually specializes in a narrow field, such as art on paper, oils,
needle art, etc.
Cotton Linters
Cotton fibers adhering to cotton seeds after the
ginning operation. The fibers must be removed from the cotton seeds
before they are pressed for cotton seed oil . Cotton linters are used
to make rag paper. Rag mat board is made entirely from cotton linters
and buffering agents.
Deckle Edge
The irregular edge of handmade papers. Machine
made papers can have imitation deckle edges produced mechanically
after the paper is dried. Art on deckle edge paper is often float
mounted so that the irregular edges can be viewed.
Dustcover
Paper applied to the back of the picture frame.
As the name implies, its purpose is to keep dust from entering through
the back. It also inhibits the entry of insects.
Face Paper
The outer layers of paper on mat, mounting and
filler boards. The front face paper on mat boards are available in
many colors, patterns and textures that enhance framed art.
Fillet
A narrow strip of wood placed in the rabbet of
a molding or inside a mat opening to provide
an accent color or texture.
Float Glass
Glass produced by floating molten glass on a
bed of molten tin, resulting in an optically
flat surface. Float glass is the picture framing standard glass.
After cooling the glass may be treated to control light reflections
and increase ultraviolet light filtering properties.
Float Mount
Mounting artwork on a decorative mat so that
all edges are visible after the art is framed. Most commonly done
with art on deckle edge paper or very old
documents where the edge has deteriorated through repeated handling
or the actions of small animals.
Fugitive Colors
Pigments and dyes that fade or change color upon
exposure to light (particularly ultraviolet) and/or heat. Artists
and printers of reproduced art are not always sensitive as to whether
or not the inks or pigments they use are fugitive. Ultraviolet
blocking glass is an economical way to preserve color fidelity.
Glazing
A transparent material used to cover some artwork.
The most common materials are float glass
and acrylic. Acrylic is lightweight and colorless, but not optically
flat. Low iron content float glass has
recently become more available so that it is now possible to use optically
flat, almost colorless glazing in picture framing. Artwork on
paper should always be covered with glazing to protect the paper.
A spacer should always be included between the art and glass to prevent
the art from adhering to the glass. The spacer can be a window
mat or a small strip of acrylic.
Glue
Adhesives made from animal
bone and skin. Often it must be heated before it is capable of being
applied to the surfaces which are to be joined.
Hinge Mount
A low intrusion method that attaches art on paper
to the mounting board using Japanese paper
and cooked starch paste. A strip of long
fiber, acid-free paper is torn so that the fibers stick out well past
the edge of the paper. A small amount of cooked starch
paste is used to moisten the fibers at one end. The strip is placed
on the art so that the fibers touch the paper of the art just past
its edge. Another strip of torn paper is attached to the first strip
and the mounting board with starch paste
well away from the art.
Japanese Paper
Thin, strong papers made in Japan from native
plants among which are kozo (paper mulberry). The papers are handmade
from long fibers. When torn, rather than straight edges, the edges
are very feathery with long fibers, which do not tear. This paper
is used for hinge mounting and mending art
on paper.
Lignin
Lignin occurs in most plant cell walls and gives
structural strength to the plant. Lignin is unstable and becomes acidic
as it breaks down. The acid that forms can migrate to framed art unless
the mat is buffered, turning the paper brown and causing it to dry.
Molding
An ornamental strip used to embellish a surface.
A molding may be wood, metal, plastic, or other materials.
Molecular Trap
Natural or synthetic aluminosilicates (zeolites)
having uniform, small pores. They are important in picture framing,
since when they are added to mat board and backing board, art harming
airborne pollutants that enter the pores can be immobilized.
Mylar®
A registered trademark of Dupont for polyester
films. Mylar-D is the most stable polyester film and is used by picture
framers to encapsulate art on paper, paper documents or other planar
objects where it is important to be able to view the entire object.
Non-glare Glass
Glass where one or both surfaces have been treated
chemically or mechanically to slightly roughen the surface, causing
reflected incident light to be dispersed in all directions. Because
the glass surface is not smooth, art images behind the glass tend
to be softened. The softness depends on how far the art is from the
glass. No more than two or three mats are recommended to be used with
non-glare glass. Objects in deep frames (shadow boxes) should never
be displayed with non-glare glass.
Optically Flat
Produces distortionless reflections.
Polyvinyl
Adhesive
A water based adhesive
made from polyvinyl acetate. It is used to bond porous and semi-porous
materials such as wood, paper, cardboard, cloth and leather. When
dry the adhesive is an almost colorless, translucent,
flexible, acid-free solid. Polyvinyl adhesive
remains flexible for long periods of times, perhaps 300 years according
to some experts researching adhesives for
conservation book binding. This adhesive
is almost universally used to join picture frame corners.
Premium Clear
Glass
Float glass without
special treatment. It reflects about 8% of incident light and blocks
about 42% of incident ultraviolet light.
Preservation
Framing art and objects with materials and methods
that provide a stable environment and minimize the deterioration of
the framed item.
Reversible
Any method used to mount art or objects that can
be undone in such a way that essentially no harm is done to the art
or object. Methods include hinge mounting
works of art on paper, stitching textiles to mounting boards with
cotton thread and pinning needle art with stainless steel or nickel
plated brass ball point pins. Adhesive tape
and glue are not reversible.
Starch Paste
Paste made by cooking refined rice starch or wheat
starch granules with a small amount of water until they burst and
a gelatinous paste is formed. The paste is used as a hinging adhesive
in preservation framing.
Ultraviolet
Blocking
Glass that is treated, usually with an applied
coating, but may have a plastic filter sandwiched between two pieces
of glass, that prevents 97% of ultraviolet
radiation from being transmitted through the glass. UV blocking
glass is the glazing of choice for art that
will be displayed in daylight, fluorescent or halogen lighting.
Ultraviolet
Radiation
Very energetic electromagnetic radiation just
beyond the blue end of the visible spectrum, it is very damaging to
fugitive pigments and dyes.
Window Mat
Mat board with a hole (window) cut in it through
which the framed art is visible. The color of the mat is chosen to
direct the eye of the viewer into the art. The width of the mat should
be at least 2 inches, but in harmony with the dimensions of the art
and the width of the frame molding. The mat
also provides space between the art and glazing.
For preservation framing, the mat board
should be made from purified alpha cellulose
or cotton linters. |
