Parchment Museum

Christopher Clarkson, "Rediscovering Parchment: The Nature of the Beast."  The Paper Conservator.  16 (1992) 5-16.  [A PDF file in the Canvas "Files" folder.]

1)  "Parchment paper" is not actually parchment, which is made from animal skins.  Real parchment (i.e., prepared skins of calves, sheep, goats, etc.) first began to be replaced by paper between 1150 CE and the late 1500s, beginning in Moorish Spain (medieval Islamic MSS are commonly written on paper) and it was gradually adopted to create cheaper manuscripts and especially printeed books in France, Italy, Germany, and finally England.  When smooth, white machine made paper largely displaced somewhat rougher-surfaced linen-rag hand-laid paper in the early 1800s, people seeking a more traditionally "retro" writing surface were sold papers mechanically finished to have more surface texture and colored off-white or light tan, imitating the superficial appearance of real parchment.  Over time, as real parchment ceased to be part of our typical writing/reading experience, "parchment" became a term used solely for those intentionally exotic appearing papers, to distinguish them from the uniformly smooth, white paper we typically buy for photocopying and computer printers, and for ordinary writing.  For bibliographic descriptions, always be careful to distinguish real parchment from paper, and only use "parchment" to describe writing surfaces and bindings made from animal skins.  (Clarkson's "Rediscovering" title suggests that librarians and book collectors were encountering actual parchment as a novel substrate for old texts as late as the 1990s and needed guidance about how it behaves differently from paper!)

2)  Though animal skins had been used for centuries as a durable substrate for writing and painting, mass produced and finely finished parchment originated in Pergamum after the Egyptian emperor cut off Pergamum's source of papyrus around 200 BCE in order to strengthen the power of the great library of Alexandria (according to Pliny's Natural History XIII.11).  The medieval Latin name for parchment was pergamenum.  Spreading rapidly to Europe, parchment manuscripts coincided with the rise of Christianity and they were used to make the earliest surviving Christian biblical codices (Codex Vaticanus, Codex Sinaiticus, Codex Alexandrinus, and Codex Ephraemi Rescriptus, circa 325-450 CE).

3)  Parchment can be made from almost any untanned animal hide that has been properly fleshed and de-haired, stretched and dried and smoothed.  The most common hides encountered in surviving medieval MSS are calf, sheep, goat, and pig (Christina Duffy, "Here's Looking at You Kid: Under the Microscope with Leather," British Library Collection Care Blog, October 30, 2013).
Also see "Leather Identification," Lili's Bookbinding Blog, January 19, 2009.

4)  Parchment is humidity-sensitive: 55-65% humidity is ideal.  Lower humidity causes parchment bindings to crack and boards to detach.  Higher humidity causes parchment leaves to curl until books cannot be closed.

5)  Parchment, like paper, can be called a "support" or "substrate" because it exists to support ink or painted pigments.  When parchment is deformed by fluctuations in humidity, ink and pigments can be distorted or sloughed off entirely.

6)  Parhment does not want to lie flat, even in ideal humidity conditions.  Scribes worked with a knife in one hand and a pen in the other, using the former to control the parchment (and to "erase" errors by scraping off the ink), and the latter to form the letters.
https://medievalfragments.files.wordpress.com/2013/10/lawrence_of_durham.jpg
Lawrence of Durham, Durham, University Library. Ms. Cosin V.III. 1. f. 22v. from Irene O'Daly, "Writing the Word: Images of the Medieval Scribe at Work," Medieval Fragments [U. Leiden Blog, ] 10/13/14. https://medievalfragments.wordpress.com/2013/10/18/writing-the-word-images-of-the-medieval-scribe-at-work/ 

Key Parchment Features and their Terms of Art
Hair vs. flesh side--rougher grain/smoother grain and darker/lighter (Figs. 16, 17 and see 25, 26 for matching openings hair-hair, flesh-flesh, i.e., "Gregory's Rule")
Flesh wounds, sewing and demilune scars or "flaymarks" (Figs. 3, 4, 5, 15, 20, 22, 23, 29, 32, 33, 34, 35a-b, 36-39a-b).
Artery, vein and trapped blood traces (Figs. 6 & 14).
Flank, spine, and pelvis traces; neck rings; leg gaps (Figs. 7, 8, 9, 10, 111, 12).
Parchmentiers' ID marks--intentional codes to identify maker (cf. papermakers' watermarks and countermarks) (Figs. 18a-b, 19).
Grain-split skins (often mistakenly called "uterine vellum" (Fig. 27a-b, 28, 30.
Pigment and iron-gall ink corrosion of parchment substrate (Fig. 41, 42).
Post-production damage due to spiders, mold, rodents, burns, sneezes, hot wax, etc.  (Figs. 2 & 43-54a-b).
Parchment Museum Exhibits
1)  Pre-parchment writing surfaces:
Cuneiform on Stone (King Ashurnasirpal II inscription on "Winged Genius,"  [Neo-Syrian, modern Iraq, 883-859 BCE] Walters Art Museum (Henry Walters 1923)
Cuneiform on clay tablets (Goucher College Library, Art Museum Collection [ca. 1000 BCE]
Palm-Leaf Sura, Thailand, [C19 CE]
2)  Full calf parchment sheets: rough finish and manuscript finish (Jesse Meyer, Pergamena Parchment, Montgomery NY [family business since 1550, Eisenberg, Germany])
3)  Pre-Codex parchment scrolls: Torah fragment (faulty), Davarim (Deuteronomy), C20; Ethiopian magic scrolls, C19-20.
4)  Large/small, thick/thin medieval parchment examples: Antiphonary leaf (Italy, C14 CE, 50 x 14 cm); miniature breviary gathering (12 leaves, ca. C14)
5)  Water damaged parchment: Psalter, Italy?, C14 CE? (Psalms 56-57, 12 x 8 cm.)
6)  Individually commissioned large MSS (over 20 cm and many hundreds of leaves): Aristotle, "Relatio" ("Relations," one of his four "Categories," usually several hundred leaves per MS), Gothic script heavily abbreviated; Code of Justinian (529-534 CE), Book 1 (of four books, usually several hundred leaves per MS), Gothic script binding fragment, 20 x 26 cm / leaf or 20 x 52 cm / bifolium sheet) 
7)  Leaves from two eearly "pescia"-produced Bibles for Paris University students: ca. 1250 CE, "Matthew XV" ["Matth" header? 9.5 x 6 cm, top-edge heavily cropped, 49 ll./page]; "Isaiah" XVI and XVII ["ISA" header, 11 x 7 cm., 45 ll. / page]  [NOTE page design similarities: columns, text block size, polychrome headers, polychrome "versals" (Roman numerals indicating verse numbers)]
8)  Horae or "books of hours," the most commonly produced surviving medieval manuscript books:  various leaves from Italy, France, and Northern Europe, C14-15)--note varieties of Gothic scripts, similarities of page design (single-column text block, fore-edge marginal decoration, use of liquid gold, red/blue versals, penwork on initials).
9)  Medieval-to-Early-Modern Transition: two 1470s manuscripts on parchment and paper in Gothic and Humanist scripts:
MS bifolium on parchment "after 1472" (dated), Offices for St. Bernardinus, 5th lesson, Gothic script;
Pseudo-Prosper Acquitanus (ca. 390-463 CE, "De vita contemplativa," MS on paper, ca. 1475 (Gwara p. 150), in Humanist "litterae antiquae" (mimicking Carolingian script, ca. 800-1100 CE) in opposition to Gothic "litterae modernae" [used early by Poggio Bracciolini, 1380-1459, scribe for Vespasiano da Bistici of Florence, 1422-1498.]  Ancestors of Gothic type font used by Gutenberg (Heidelberg, 1454, and successor printers), and Roman minuscule type fonts used by Nicholas Jenson (1420-1480) and Aldus Manutius (Venice, 1449-1515; Aldine Press, 1495-1506).  [NOTE: this leaf is one of four known groups of leaves from this MS,  originally broken up and sold by notorious biblioklast Dr. Otto Ege.  The others are currently in the collections of University of Colorado; Newberry Library (Chicago); and Toledo Museum of Art.  Scott Gwara,  Otto Ege's Manuscripts (Caycee, S.C.: University of South Caroline Press, 2013), Handlist Entry No. 94, p. 150.  As a whole manuscript, once listed as De Ricci no. 31.]]