Materials used for the Old Testament involved skins. Papyrus rolls were used for the original Septuagint. Papyrus rolls were used until the 1st century A.D. Papyrus Codices were used in the 2nd to 4th centuries A.D. Vellum and parchment were used in the 4th to 8th centuries. Paper from flax was used in the 8th or 9th to the 12th or 13th century. Paper from linen rags was used in the 14th century. Vellum with paper was used until the 15th century. Vellum was displaced by paper after the 15th century.
Regarding the size and form of letters, Uncials, (all capitals) were used up to the 10th century. Minuscules, (small letters) were used thereafter.
Regarding punctuation, words were written with no spaces between. Words were written with a space to indicate a “pause.” Words were written with a space between in which was a dot. Then in succession came commas, colons, question marks, etc. In the 7th or 8th century, accents and breathing marks were added.
Regarding text divisions, by the 4th century, the Gospels were divided into long and short sections. By 458 AD, the Epistles of Paul were divided into sections for public reading. In 590 AD, the Acts and general epistles were similarly divided. In the 7th century, Lectionaries were made which are service books or volumes containing selections from parts of the New Testament to be read throughout the year in church services. There are about 1565 lectionaries known at the present.
The dating of manuscripts was determined by material used, size and form of letters, punctuation, text divisions, spelling, color of the ink, color of the parchment.