What camera and materials did August Sander use?

From a comment on a discussion thread at photo.net regarding the subject:

According to a letter Sander wrote in 1925 to Prof. Dr. Erich Stenger, "I use Zeiss lenses, an orthochromatic plate with corresponding light filter , and clear fine grained glossy paper. I make my photos on 12x161/2 or 13x18 plates, enlarging them to 18x24." quoted on p. 108 in Sander, publ. by Taschen

The next comment provides a further interesting possibility:

About 20 years ago I saw a show of original Sanders prints and was struck about something unusual that I never detected in offset reproductions of his work. The lighter areas looked "porcelain" and I wondered what caused that effect.

I've pondered this frequently over the years, and the only explanation I can muster is that he used an enlarging lens with some aberrations that spread a little light from adjacent dark areas into the highlight areas. It darkened the edges of the lighter areas very slightly, but enough to give my the sensation of a glassy porcelain. For all I know, he may have even used his camera lens as an enlarging lens. That was more common then.

All this is conjecture, but someone investigating his work should look into what gave his prints that different appearance. I'd love to hear of anyone's actual research into this to satisfy my own curiosity.

This shows how important it is to view original prints when trying to determine working methods.

From another piece about Sanders:

Sander did not use the newly invented Leica camera. Instead he remained devoted to an old-fashioned large-format camera, glass negatives and long exposure times. This allowed him to capture minute details of individual faces.