I am not sure if this set of two vanity bottles is white glass, opal glass, milk glass or something else entirely. They are relatively heavy (not delicate like porcelain) and each has the same marking on the bottom plus a number. The necks of the bottles are threaded so the tops screw on. The taller bottle is 6" with three illustrations and the smaller bottle is 3 1/2" with five illustrations. The illustrations are of couples dressed in clothing from various eras. I can't remember when or where I acquired these two bottles and I haven't seen anything similar in researching the Internet. Any information would be very much appreciated.