1)  What can we learn from the ink/pigments, and "substrate/support" (parchment, paper, wood panel, etc.)?  How are these materials typically described?

Ink color and probable composition: look for black inks as the most common primary text vehicles--brown usually means a vegetable black pigment has oxidized; corrosion eating into the substrate suggests "oak gall ink" corrosion (iron sulfate and oak galls are acidic in presence of vaporous or liquid water).  Lamp-black inks resist oxidation more successfully.  Red and blue inks are most commonly used for "rubrication," to distinguish sections of a larger text and to set off directions/responses from main liturgical parts of the Mass, etc.
How do the color patterns organize the text?  Compare with mise-en-page and textual/iconographic analysis evidence.

Pigments in illuminations: pigment chemistry is immensely complicated and informative.  Some pigments are cheap but colorful.  Others are both colorful and extremely expensive.  To analyze pigments, make a list of the specific colors in use on each side of the leaf.  If you have more than one leaf or a whole MS, you  can recreate the array of pigment pots on the scribe's work table.  If you have an X-Ray Fluorescence machine, you can ask it what the main color agent is, and (more importantly) what impurities are in that particular batch of color, a veritable "fingerprint" of the batch wherever it was used.  The proportion of expensive pigments (including gold) in a MS can suggest the status of the patron or intended customer.  One pigment, in particular, lapis lazuli (known as "ultramarine" from "over the sea") typically cost thousands of times more than gold.  Click here for the PDF of Amy Baker's "Common Medieval Pigments" (first published online in 2004 on Cochineal, the U. Texas, Austin online journal--now available via DScholarship@pitt.edu).

Parchment: Look for hair-side (follicles, darkening) and flesh-side--can you identify the animal whose hide was used (Christina Duffy, "Here's Looking at You Kid," British Library, 30 September 2013)?  In a manuscript opening (verso on the left of the sewing, recto on the right) flesh side faces flesh side or hair side faces hair side--can you tell which edge of the leaf faced the binder's sewing and which faced out toward readers' hands?  [Named "Gregory's Rule" for its discoverer, a German-American manuscript scholar named Caspar Gregory (1846-1917).]   Quality of preparation--is it thin or thick, and if thick does that correspond to some demand of its intended use?  Or is this an inexpertly prepared piece of parchment?  After European printed books on paper become the most common substrate for reading (roughly mid-1400s), parchment manufacturing becomes increasingly poorer in technique except in some very rare instances.  Is the parchment smooth or rough, especially on the hair-side?  Very thin, very smooth parchment is sometimes thought to be "uterine vellum" (calf-skin taken from unborn animals), but it has been pointed out that so much parchment of that quality still survives that producing it that way would have wiped out Europe's cattle herds.  Modern parchmenters, like Jesse Meyer at Pergamena Parchment, suggest that super-thin parchment was made by splitting the hides on edge, perhaps more than once.  Imagine the technique!

How tall and wide is your leaf at its tallest and widest points?  Measure your leaf carefully in centimeters, recording the height before the width.  Leaves can grow smaller because edge damage was cut off during rebinding, or because the person who cut the leaf out of the binding left some behind where it was sewn in.  But a leaf can never get bigger.  Leaf size, like parchment and ink types, are fundamental to every manuscript's identity.  (Also see "text block size" in mise-en-page.)

Damage--look for human skin oils on the outer edges and especially upper corners of leaves (why?); look for water damage (wrinkling or "cockling," shrinkage, ink loss).   Look for holes or tears in the parchment.  Were they present when the scribe was writing, in which case the text will go around the gaps, or did they occur after writing, in which case there will be loss of text.
Click here for some terms and further guidance if you want to explore parchment.

Paper: hand-laid papers (roughly pre-1800) are most common after the fourteenth century.  Click here for a chronology of paper making from C1 CE China to Europe in about C8 CE, possibly involving the capture of Chinese papermakers by Islamic army at Battle of Tharus orTaras River in modern Turkmenistan.  The first Italian paper mill became operative in the 1260s, and up to 8 Italian mills were active by the 1270s, but paper was thought too fragile for good work compared with parchment.  Paper MSS are rare until C15.  Hand-laid paper can be detected by shining a light from behind the leaf to see the chain-lines, and sometimes the water-mark, left by the paper mold.  Chain lines are the thickest/brightest and run either vertically or horizontally on the leaf.  Much thinner "wire lines" are made by the fine screen held up by the thicker chains, and they run perpendicular to the chain lines.  Watermarks are located on a leaf in patterns related to the chain lines and both are determined by the scribe's (or printer's) "format," the size and text orientation planned for the book.  Printers organized their output for binders by printing "signature" letters and numbers at the bottom of leaves indicating their presence in a quire or gathering of folded leaves in groups of 2, 4, 6, 8, etc.  The signatures usually look like a, aii, aiii, etc. then b, bii, biii, until they hit the z signatures, perhaps followed by A, Aii, Aiii etc., AA, AAi, AAii, AAiii, until perhaps even ZZZZZ, ZZZZZi etc. in a really big edition.   Signatures' presence at the bottom of a page immediately tells you it's a printed leaf, no matter how good the type is at fooling your eye.  Scribes used "catch-words" to organize their quires or groups of leaves for union into a whole MS, writing at the bottom of the last quire page the first word or phrase to be found at the top of the first page of the next quire.  Some printers also used catch-words to aid binders, so be careful!  See this quick guide to format determination.