You can find it on the PBS website here:
One critique of the documentary is that it does not mention the influence of the rise of Christianity in the popular use of the codex and tends to present the Christian medieval period in Europe as a setback in literacy and book production in comparison to the classical Roman period. At the same time it extols advances in the Islamic world (while also explaining lack of literary production there due to concern for proper transmission of the Koran) and in China (rightly, for the invention of paper). Still, it recognizes that with the technological innovation of the printing press literary and book production in the West exploded.
Also interesting to see the art historian and calligrapher discuss and demonstrate the physical experience of writing on various surfaces (papyrus, vellum, ancient paper).