The word papyrus refers both to the writing support invented by the ancient Egyptians , and the plant from which they made this material. Excavators of a tomb at Saqqara discovered the earliest known roll of papyrus, dated to around 2900 B.C., and papyrus continued to be used until the eleventh century A.D. even as paper, invented in China, became the most popular writing material for the Arab world around the eighth century A.D. In ancient Egypt, texts could be written on papyrus in hieroglyphs, hieratic script, or Demotic script, and later papyrus was used in Greek , Coptic, Latin, Aramaic, and Arabic documents. With minor variations, the papyrus roll was produced essentially the same way throughout its approximately 4,000-year history. In addition to its function as a material for writing, papyrus was used in rope, basketry, sandals , and other everyday items.
The botanical name for the papyrus plant is Cyperus papyrus, denoting that it belongs in the large Cyperaceae family of sedge plants. Although today the plant no longer grows in the Egyptian Nile Valley, it is generally accepted that during antiquity it was common and indigenous to the area. While papyrus grew wild along the Nile, the possibility that it also may have been cultivated for use in papermaking has been explored but remains an open question.
Papyrus plants are native to river banks and marshy areas as they consume great quantities of water. Water and nutrients are carried from the roots, via a system of longitudinal fibrovascular bundles, up a thick and tapering triangular stalk that measures around 5–8 centimeters in diameter at its base to the wide flower head, or umbrel, at a height of around 4 meters (or 13 feet). The tough green rind of the papyrus stalk encloses the white pith, from which the papyrus sheet is made. The pith is composed of the rigid ligneous and cellulosic fibrovascular bundles, and empty parenchyma cells with cellulose and hemi-cellulose walls, which function as air passages and give buoyancy to the stalk.
The morphology of the papyrus pith is what lends a papyrus sheet its characteristic crisscross pattern: the fibrovascular bundles are the more substantial woody striations running horizontally across the recto of a papyrus (and vertically on the verso), and the parenchyma cells are the paler, more delicate “filling” between the striations. The crisscross structure is formed by creating a sheet with two layers (for the majority of papyri) of pith slices arranged perpendicularly. While the arrangement is clear, the exact method of papyrus-making is, unfortunately, undocumented by the ancient Egyptians, and therefore some of the details of the procedure have been pondered over by modern scholars.
The earliest description of papyrus-making comes from the Roman naturalist Pliny the Elder. His account, dating to circa 77–79 A.D., leaves some aspects of the process open to interpretation, but modern experiments in papyrus-making as well as instrumental analysis of historical samples have led to strong conclusions about how the ancient Egyptians produced their papyrus. After the plants were gathered and while the stalks were still green, a 20–48 centimeter section of the stalk was cut (the maximum length being the maximum height of a papyrus scroll) and the outer rind of the plant was stripped off . Thin strips were produced either by slicing the pith lengthwise, or by using a needle to peel the pith, like unrolling a coil, from the outside to the center. Modern experiments have shown that both methods are possible and that great skill is required to create thin and uniform strips.
Individual sheets were formed by laying the strips side by side, first in one vertical layer, and then in a second horizontal layer. It is generally accepted that no adhesive was used; however, using more damp or pre-soaked strips of papyrus leads to better adhesion between the layers, perhaps by facilitating physical bonding as the moisture causes the parenchyma cells to swell and then lock into each other upon drying. Some modern researchers have found that pressing until dry is critical for sheet formation, but Pliny claims that sheets were pressed together and then dried in the sun; the exact method of pressing and drying by the Egyptians is unknown.
Sheets of papyrus were then made into rolls; a common size is twenty sheets to a roll. This was done by overlapping sheet edges by 1–2 centimeters and adhering with a flexible starch-based paste. Blank rolls were produced, but occasionally already inscribed papyri sheets were added to previous rolls, or adhered together to make a new roll, among other alterations. Papyri were always rolled with the vertical-running pith on the outside because of the natural tendency of the sheet to curve in that direction; inscriptions and illustrations on a papyrus roll are generally on the horizontal side of the sheet, where they would be protected when rolled up .
The text of a papyrus was written by a scribe in black and red ink . The black ink contains a carbon-based pigment, made either from incinerated vegetable material or from soot. The red ink tends to be either red iron-oxide (anhydrous oxide of iron) or red ocher (hydrated oxide of iron). The painter’s palette, which he employed in painting the illustrations on the papyrus, can include several colors . Numerous variations on the pigments used for the Egyptian color palette have been discovered by conservators and scientists but generally, these colors often include white, made from calcium carbonate or calcium sulfate; blue, a copper silicate which is the earliest synthetic pigment, called Egyptian blue; green, often another silicate called green frit, similar to Egyptian blue, or copper chloride–based green pigment; yellow, either yellow ocher or orpiment; red, occasionally a more orange-red pigment called realgar in addition to the iron-oxide or ocher reds; and various iron-oxide or ocher browns.
Less analysis has been done to identify Egyptian pigment binders for a number of reasons, including difficulties in evaluating greatly aged samples and the requirement for destructive analysis of samples, even the tiniest of which can be prohibitive in a material as precious as a painted papyrus scroll. However, samples that have been analyzed indicate that the most common binder was acacia gum, some varieties of which are native to Egypt, although not overly prevalent. Gum tragacanth has also been identified as a less common binder. The Egyptian painter used a brush made of a rush with its tip chewed to separate it into fibers.
Many aspects related to the materials and technique used in making papyrus scrolls, as well as their storage and handling in ancient and modern times, contribute to their appearance today. While newly made papyrus is generally cream or slightly yellow-colored, today many papyri are much darker . Factors contributing to the darkening of papyri include natural aging of the ligneous material, contact with substances in the burial environment, past preservation strategies in private and museum collections including the use of adhesives for overall mounting, contact with acidic mounting materials, and thickness of papyri, as thicker papyri have been noted to darken more than thin ones. Papyri that have been overexposed to UV suffer degradation of the cellulose interfibrillar material, and become weak and vulnerable to breakage and simply turning to dust . In addition, the opaque watercolors used on papyri are often subject to flaking as the gum binder becomes desiccated or as the underlying papyrus support becomes structurally less stable. In light of these challenges, the papyri that have been spared damaging treatments and have been stored in safe environments can be preserved remarkably well, especially for organic materials that are multiple millennia old.