The Aldrevandini Beaker from Venice ca 1330, British Museum
A cup from Museum of London, ca 1250-1325
A cup from Institut für Realienkunde des Mittelalters und der frühen Neuzeit
Beaker by Aldrevandini, second half of the 13th century, image from Bildindex.de
I spent quite a while looking for glasses with the rigth beaker shape, but they were nowehere to be found. I didn't even find the right shape among historical reproduction glass. Probably beace they are more interested in reproducing the "funny" shapes, siuch as this one, which I also have a repro of.
I was also a bit wary about hardening glass paint in the oven on a historical repro glass, since I don't know how they would react to the heat. Still, I would have tried it if I had found the right shape.
I trawled internet auction sites for something with a shape that would work, but in the end I accepted my fate and ordered beer glasses from barshopen. I've ordered glasses for painting from there before and I know that they are sturdy. The beaker shape isn't very popular for beer glasses either and this was as close as I could get:
As you can see it has cut and frosted parts, which isn't very medieval. it also has the amount engraved on it, but both these could be hidden with paint. The shape was the best I could get so I went for them.
I used ordinary paint for glass, the kind you harden in a household oven. I had them at home already due to previous painting projects. The white was paint and the other colours pens.
The arms are of course those of Gotvik, and the text says: Gotvik Baronia Clarissima, that is: "Gotvik, the most shining barony", which is what the barony of Gotvik usually present themselves as.