Thx, Michael. I made a small error too, my Jaroslav piece is a vase not a bowl! I have his bowls too though! The labels could in my oinion be time related and are never indications of quality really: red, gold, there are white, black too (slightly different square labels). All are good and pieces with any labels are equally worth collecting if interested in Skrdlovice glass, you will have them all on your shelf soon the way your collection is going!
Robert (bOBA)