Last year I acquired from an antiquarian shop in Amsterdam several gelatin silver prints made in 1910 of a shaving brush factory in northern China. The factory was operated under a concession to the British Crown. Below are scans of two of those prints. The first shows workers hand-tying knots made of black bristles, and the second is an interesting group photograph that includes English businessmen (and a dog). The detail in the original prints is amazing.
1910 Chinese shaving brush factory photos