|
Papyrus is made from thin strips of the pithy center
of the papyrus plant. The strips are placed in an overlapping,
cross-laminated structure, then pressed or beaten to
bond and dry them into sheets. If the papyrus stalk
is freshly cut, the strips will adhere naturally thanks
to the sap, but if it is dry, a paste adhesive
is used. Some surface sizing
is done with a rice starch paste, then the surface is
rubbed with pumice stone.
Papyrus is quite weak when subjected to any stress and
can break easily. Papyrus was used in rolls and in the
codex form, with codices often formed by stab sewing
along the back edge or sewing the leaves together in
small gatherings.
Identification
Papyrus can be identified by examining a sheet over
a light table or by holding it up to the light. The
cross-laminated structure of the pith strips becomes
easily apparent. Papyrus must be dated in combination
with contextual clues and in reference to known examples.
In many cases old papyrus has deteriorated into small
fragments and so must be handled with care.
Condition Concerns
Ancient papyrus may be desiccated and brittle as well
as discolored. Papyrus may be naturally acidic because
of its high lignin
content. Lignin also causes papyrus to darken when exposed
to light. Papyrus may have a strong tendency to curl
at the edges unless restrained, and the edges fray easily.
In the 19th and early 20th centuries papyrus was often
stored, handled, and displayed by taping or gluing it
to cloth, cardboard, cellulose nitrate,
or hardened gelatin
sheets or—most commonly—by sandwiching it
between pieces of glass sealed around the edge with
paper tape. Acids can migrate into the papyrus from
these materials.
|
Papyrus
