44 Library, MC-522
1408 West Gregory Dr.
Urbana, IL 61801
Oak St. Library Facility
OSLF, 2nd Floor
809 South Oak Street
Mail Code 527
Champaign, IL 61820
Glossary of Terms
Acid-Free refers to paper-based materials that do
not contain free acid and have a pH value of 7.0 or higher at the point of manufacture. These
materials may, however, become acidic over time due to a lack of buffering agents (
Alkaline Reserve) and the presence of
component of low-quality paper) or certain additives.
Acid Migration is a process that occurs
when acid transfers from a material containing higher acidity levels to one containing less or no
acidity. This may occur through off-gassing (gaseous transfer) or physical contact.
Adhesive Binding is type of binding
in which single leaves are secured together solely with an adhesive applied to the textblock's
spine edge. Animal glues,
acetate (PVA) glues, and hot melt adhesives have all been used in the past for this type of
binding, sometimes refered to as "perfect binding". Sections with perforations along the folds (or
adhesive penetration into the folds to hold each section together) is also a type of adhesive
binding, commercially known as perfo-, burst, mecha-notch, or perfopunch binding. See also
Double Fan Adhesive
Alkaline Reserve is a substance (commonly a calcium or magnesium salt) that has
been added to the paper matrix either during manufacture or after, which neutralizes active acids
and reduces the potential for the embittlement of paper. Papers that have an alkaline reserve are
referred to as Alkaline Buffered.
Archivally Sound are terms that imply that a material or product is permanent,
chemically stable, and durable. However, there is no standard by which a material can be referred
to as "archival". Therefore, terms such as
alkaline buffered, or
lignin free may be better guides for the permanence of a material.
Archival Papers (such as Permalife,
Perma/Dur, or archival tissues) are made of high quality paper fibers and frequently have an
alkaline reserve (pH 8.5). They are used for
interleaving sheets between acidic documents, for tabs for forms placed in
contact with archival materials, and to make simple wrappers when more protection is desired than
interleaving. It is important to use archival paper for preservation photocopying or for the
printing of new publications.
A text that has
Artifactual Value is important as a physical object, in addition to (or rather
than) being important for the information it contains. Examples of this include copies of books
signed by the author, original photographs, marginalia by famous owners/researchers, and highly
Barrier Sheets are pieces of
archival paper inserted in a book or placed between documents to prevent
the transfer of media, acids, or damaging gases from one material to another. See also
Backing is the process of shaping a ridge or
shoulder on each side of the spine of a
rounding it, and prior to lining it. Backing accommodates the thickness of the
which they swing. Backing also helps to prevent the
spine of the
text block from collapsing into a concave shape over time. See also
Board is a general term used for any stiff material used to
form the foundation for a book's
case. They are
made of various pulped or laminated fibrous materials pressed into large, flat sheets, which are
then cut to size and covered with
paper, or other materials, to form the case. The boards are referred to separately as the front and
Book Cloth is specially prepared cloth material
used as a covering material for the
case. It is a
thin, woven cloth that has been dyed, filled, impregnated or coated with some compound, and
subjected to heat and pressure. Book cloth falls into three main categories: starch-filled,
acrylic-, pyroxylin-, or vinyl-impregnated, and plastic coated. Book cloth is lighter weight than
and is available in a range of grades and colors.
Boxes are containers used to hold loose sheets, documents,
maps, or fragile books. Commercially available and hand-made boxes are constructed of many
different materials and in many styles, including light-weight 4-flap boxes, heavier phase boxes,
and sturdy clam-shell/drop spine boxes.
Bristol Board is a high quality heavy
weight paper, sometimes made with cotton fiber prepared or glued together, usually with a caliper
thickness of 0.006" and up.
Brittle Paper occurs when acidity increases
causing the molecular structure of the cellulose fibers to weaken. This results in paper with
reduced fold-endurance which breaks easily when it is bent or folded.
Buckram is a heavy-weave cotton cloth filled,
impregnated, or coated with different compounds (mainly, starch and pyroxylin but also other
materials) to enhance body, finish, and durability. Most bindings from library commercial binders
have buckram cloth. C-Grade buckram is a thinner, smoother cloth than F-Grade buckram, which is
heavier and the most durable.
Case of a book consists of two
and covering material (usually
leather). The case is made separately from the
block and is later attached to it in a step called
Casing-In. See also
Case binding is a method of binding in which
the case is made separately from the
textblock and later attached to it. (As distinguished from leather bindings
where the cover is assembled on the book.) The textblock is attached to its case by means of its
endsheets and an adhesive. This method is used for most in-house book repairs
and commercial bindings
Case Repair is a repair performed in-house to
restore an original hard-bound cover when the only damage it has sustained is a torn or damaged
Casing-In is the action of applying adhesive to the
outermost endpapers of a text block and fitting the text block into its case.
Coated paper is a type of paper coated with
white clay or a similar, synthetic substance to provide a smooth surface for printing detailed
illustrations. The finish is often glossy but can be dull. Most popular magazines are printed on
Consolidate a spine is to attach the loose gatherings on spine edge of the text
block to each other and to a cloth support using an adhesive.
Cover of a book is a more generic term than
case, used to
imply any protective covering used on the outside of a book. Covers may be built onto the book
(including laced-on boards and tight-back leather bindings), can be built separately from the
textblock (including most modern cases), or be of simple, paperback
Deacidification is a process that
impregnates paper with an
alkaline reserve to neutralize the active acid in the paper substrate
and act as a buffer to neutralize acids produced in the future. Deacidification lengthens the life
expectance of paper several times its ordinary life.
Disbinding is the action of removing the
textblock from its
binder by easing the
endsheets away from the textblock and by slitting the
present) with a scalpel.
Double Fan Adhesive Binding (DFA) is a type of adhesive binding
where the spine margin of each
leaf in an
textblock is exposed 1/16" or less for an application of adhesive. The margin
is exposed on both sides of each leaf by clamping the textblock on a vise-like press and then
pushing against the textblock, first in one direction, then the other, thereby fanning or
separating the edges of the leaves.
Encapsulation is process of creating a
protective enclosure for flat materials by placing the object between two sheets of polyester film
and then sealing it on at least one, but often all four edges using double sided tape, heat, or
Endsheets are the pages at the beginning and end of
a volume added to both protect the
textblock and to secure it into the
papers include both
Flat back (sometimes referred to as square back) is
textblock that has not been
Flyleaf is the leaf (or leaves) forming that part of
endsheet not pasted down to the inside of the cover boards. Its function is
to protect the first or last leaves of the
textblock. See also
Fore Edge is the edge of a
textblock, or a
board opposite from, and parallel to, its
spine edge. Fore edge is also used in a more general way to
refer to any part of a volume opposite from and parallel to its spine.
Foxing are spots or irregularly shaped stains that occur
on paper. Foxing is caused either by fungi or iron impurities in paper, thought to be introduced
during the paper's manufacture. Foxing may be controlled by maintaining relative humidity levels
Grain Direction refers to the direction
in which the majority of the fibers in a piece of paper or board are aligned and to the direction
in which the warp threads run in cloth. Grain direction in all materials used in bookbinding should
run parallel to the spine of a volume.
Gutter of a volume is the groove and
margin-space formed by the inner or back margins of pages of a
volume, closet to the
Head is the top edge of a
board, or bound volume, opposite from the surface on which the
volume rests when it is shelved upright. See also
Headband is a small ornamental band, generally of cotton or silk, which, in most
modern publisher's trade bindings, is glued on the
head as well as the
tail of the textblock's
spine. Modern headbands imitate the sewn-on headbands that
functioned to protect the head and tail of early bindings.
Headcap is the top edge of the cover's
spine that runs parallel to the top headband. See also
Hinge is the flexible part of the cover on which the
boards flex open. See also
inner hinge and
leaf or a group of leaves a strip of
Japanese tissue or linen tape is adhered
along the binding edge of the leaf (or leaves) so that the strip extends beyond the binding edge.
This can then be attached to the
textblock by pasting up the part of the strip that
extends beyond the leaf (or leaves), and adhering the strip to the binding edge of a leaf in the
Hollow is that part or space of a case binding between the
spine and the inside of the
Inner Hinge is the groove lying between a
pastedown and a
flyleaf where the
textblock is attached to its
cover. Also called a front hinge and inner joint, this serves as the
functional part of the book that allows the covers to be opened and closed.
Interleaving is the act of placing
barrier sheets of
acid-free or buffered
paper between leaves or documents to prevent the transfer of media, acids, or damaging gases from
one material to another.
Japanese Tissue is a soft, strong,
long-fibered, and often translucent paper made from the fibers of a variety of plants common to
Japan, especially the mulberry. It is available in a variety of thicknesses and colors. It is a
very versatile paper, and according to the thickness used, it can be employed for mending torn
paper, for overall lining of
leaves as a reinforcement, for reinforcing the folds of
signatures, for reinforcing fragile cloth
spines, or for mending
Kraft Paper is a strong brown machine-made
paper widely used for wrapping purposes, and in publisher's bindings for lining the inside cover
spine (spine strip) of a case-bound book.
Leaf is a single sheet of paper or half of a folded sheet of paper.
Leaf Attachment is the structural
method used to hold the pages of a volume together - creating a
textblock. Some leaf attachment methods only employ
dhesive to hold the pages together. Other methods employ thread that is used to sew together the
pages of the text block.
Leather has been used as a book covering material for
many centuries. There are many different methods by which animal hides are tanned or tawed to
produce leather, resulting in a wide variety of strengths and aging properties.
Lignin is a component of woody plant fibers used to make
most modern papers (not present in 100% cotton or linen paper). Its presence in paper contributes
to chemical degradation of the paper.
Lignin Free refers to paper that contains no lignin. It may be 100% cotton or
linen fibers or be chemically processed to remove the lignin from the wood pulp.
Margin is the space around the edges of a page outside the printed or written
matter. The four margins are commonly designated as: top margin; bottom margin; fore edge or outer
margin; and inner or gutter margin.
Milling is a method used by library binders to remove
leaf attachments and prepare a
double-fan adhesive binding or
oversewing. The milling machine clamps the textblock,
spine down, and moves it over a series of rotating blades that cut away approximately 1/32 to 1/16
inch of the binding margin, thus removing old adhesive, thread, staples, and/or the folds of
signatures. After milling, a text block is comprised of loose
Molds are microscopic fungal organisms that form masses on
the surface of paper,
book cloth, or
leather. Molds can appear black, white or brightly colored
and can range from dry and powdery to wet and slimy. Molds permanently deform the surfaces they
Mylar Laminate Cover is a covering material made by sandwiching the original paper
cover from a paper-bound volume, or the dust jacket from a
hard-bound volume, in between a laminate of polyethylene plastic and paper. This laminate is then
used in the place of
buckram to make the new cover. This product was developed to
allow libraries to retain the original artwork or text found on paper-bound volumes or dust
Notching is a method for preparing the
spine of a
textblock for adhesive binding. The binder will cut very
shallow, notches into the spine before applying the adhesive. These notches allow the adhesive to
penetrate into the pages which greatly increases the strength of the leaf attachment.
Outer Hinge is the flexible groove of covering material on the outside of a book
on which the
case board opens. Also called the outer joint.
Oversewing is a long practiced
leaf attachment method used to sew single
leaves together. This leaf attachment method was very common in
commercial binding, but has fallen out of favor in recent years except in specific cases.
Individual leaves are grouped in small (1/8") gatherings that are side sewn together. The
oversewing machine operator continuously feeds these small gatherings into the machine which sews
the gatherings together. Oversewing can be recognized by its very inflexible
spine and uneven, tight
Pastedown is the half of an
endsheet that is glued to the inside of the
pH is a chemical measure of acidity or alkalinity obtained by
measuring the quantity of free hydrogen ions in a solution. The pH scale is logarithmic (increases
by multiples of 10) and runs from 0 to 14. A pH of 7.0 is neutral, while pH higher than 7.0 is
alkaline and lower than 7.0 is acidic.
Permanent Paper is a paper that
withstands the effects of aging better than ordinary paper. It is manufactured to resist chemical
action from impurities in the paper or in the atmosphere during long term storage.
Pressure Sensitive Tape
is any tape made of a film carrier with an active, pressure sensitive adhesive applied to one side.
These tapes should not be used to repair torn leaves because the adhesives discolor and stain and
are difficult or impossible to remove.
boxes, slipcases, portfolios, or any other container that is
designed to hold and protect books, manuscripts or other archival materials. Many commercial
containers or custom-built protective enclosures are available for a variety of materials and
Polyvinyl Acetate (PVA) is an emulsion adhesive that dries
quickly and is considered permanent. It results in a very strong bond that remains flexible over
time and does not yellow.
Rag Paper is paper made from cotton or linen fibers
instead of wood pulp. Rag paper is stronger and more durable due to its chemical stability, low
acidity, and long paper fibers.
Reversability pertains to the ability to
undo a treatment or process without harming or changing the original object. Reversability is an
important principle when performing conservation treatments on items with
Rounding is the process of hammering the
spine into a convex shape preparatory to
backing. Roun ding diminishes the effect of swelling caused
by the thickness of the sewing threads or the application of glue from an adhesive binding. It also
helps to prevent the textblock spine from falling into a concave shape after years of use or of
standing upright on a shelf.
Sewn Through Fold refers to items
signatures sewn together. These items can be easily
identified by looking for sewing thread in the
inner margin of the middle of a signature.
Shoulder is the outer edge of the
spine against which the
cover board fits. The shoulder is made when a book is
Signature is two or more sheets of paper stacked and folded as a group. Also
called a gathering, quire, or section. A
textblock is made up of many signatures sewn
Spine Linings are layers of cloth and paper
used for reinforcing and stiffening the
spine of the
textblock. In many publisher's
adhesive bindings, linings may not be used
at all; the textblock is not reinforced and is held together simply with a layer of glue. Ideally,
textblock spine linings should reinforce the glue and help hold the sections together.
Spine is the space between the
boards of a
case to accommodate the thickness of the
textblock. The inside of this space is stiffened with a
spine strip, usually made of
hinge area left on either side of the spine strip allows for the
movement of the cover boards on the
shoulders of the textblock as the book is opened and used.
The outside part of the cover spine usually receives stamping for author, title, and publisher.
This term may also be used to refer to the spine-edge of an uncased textblock.
Square of the book is the exposed margin of the
turn-in along the interior of the
case not covered by the
pastedowns. The square runs along the
fore edge, top, and bottom edges of the book.
Stamping Foil is the lettering on the
spine of a volume which is stamped into the
book cloth using heat and pressure to transfer color
(gold, white, or black) from a piece of carrier film to the cloth.
Stubbing is the process of adding sheets of paper to
textblock to accommodate pockets, inserts, or gaps.
Super is an open-weave variety of coarse, sized fabric used
for reinforcing or stiffening the
spine of a
case-bound book. The super forms the first spine
lining on the textblock. The excess (super
hinge) that extends beyond the edges of the textblock spine is
used to attach the textblock into its
case. Also called mull, crash, and gauze.
Tail of a volume is the bottom portion of the cover and text block on which the
book rests when it is on the shelf. See also
Tailcap of a volume is the bottom portion of the spine. See also
Textblock is the main block of
spine linings, which is bound together and then attached to the
case. Also called the book block.
Tide Lines are irregular lines or blemishes
caused by the movement of water or any other liquid through paper and the residual stains left
behind as the liquid dries.
Tip-in, tipped-in, tipping-in is the attachment of one
leaf to another in a book at or near the inner margin by means of
a narrow strip of adhesive along the
gutter edge of the sheet.
turn-in is the part of the covering material that is turned over the outer edges
of the boards (and spine strip) from the outside to the inside. Also called a turn-over or
Conservation Information Sheet Number 1: Selected Glossary of Conservation and Preservation
Book Arts Web
Library Binding Institute
University of Kansas Preservation Department