Antique drawings on silk?

I aquired these 2 pieces at a tag-sale..They appear to have been done on silk? It almost looks like its been drawn in ink-and the material is very yellowed..There are also little "doodles" drawn on the outer edges.They are signed, but I cant make the sigs out..The backs are still some-what sealed, and i am reluctant to remove the backs. They measure about 8'x14"..They are really cool! If anybody has seen anything similar, id love some ideas on what these are..Thanks!!