These are samples (difficult to photograph to advantage) of a set of twelve Chinese paintings on pith, often refered to as rice-paper.
They were executed in about 1820 and seem to have spent most of their lives in an album, protected from the light. The colours are wonderfully preserved, though the pith itself is in original condition. They were framed up in the 1970's, judging by the frames, and they depict scenes from a Chinese opera.