..the black looks like it wore off a bit.. the designs are primitive, but just don't look modern to me.. enamel in this case is paint.. the closest enamel comes to glass is in teeth, but it's not silicon-based, it's calcium...
My understanding is milk glass first appeared in 1500's Venice, and was originally called "opal glass" ..again Europe's antiquity and lack of hard facts can really mess with our heads..[>:]
Actually milk glass has been been around since the 1500's. Most of the items that have surfaced and are available date from the 1700's and 1800's. Attached is a pic of bottle probably from the very early 1700's. Great Museum piece...
By the way, it is my understanding that those two inks were from the late 1780's to maybe 1800 something. Gary