Invented by the Chinese as early as 105 AD, early forms of paper were made of mulberry, hemp and bamboo. Before this people would have drawn and written on papyrus, silk and parchment.
Paper was first produced in Europe in Spain, at the end of the 12th century, and would have been hand-made. In 1276 a mill in Fabriano, Ancona, Italy was founded, and it quickly became a principle papermaker in Europe.
The paper Palladio used was what is known as "laid" paper. This was made by hand on a laid mould. It has strong parallel vertical lines visible through transmitted light, about an inch to an inch and a half wide. Lighter horizontal linking chain lines run at right angles to the laid lines from head to foot.
The lines, which would appear on just one side of the paper, were created by the wire of the paper-making mould, creating a rough surface. The other side would be much smoother and known as the felt side.
The newly formed paper was couched, transferred onto felts and stacked together for drying. The felt side would be the easiest side on which to draw even though the sheets may have had a slightly textured finish.
Papermaking was an important business and papermakers guarded the secrets of their trade very carefully. In 1436 anyone within a 50 mile radius of Fabriano was prohibited from manufacturing or teaching papermaking techniques.
By the time Palladio was drawing there were notable mills at Treviso, Bologna, Florence, Padua, Parma, Milan and Venice, as well as the renowned Fabriano mills. They all rose to importance due to the decline in the Moorish papermaking industry in Spain.
The fine quality of paper produced, coupled with its location, meant that Italy became the major exporter of paper in Europe. The Italian paper industry was dominated by Fabriano, who still produce paper to this day.