The Espresso 4-Piece 3 oz. Drinking Glass Set includes 4 glasses reflect the charm of Paris bistros. The designs are inspired by the designs of antique French glasses and carafes. The thick sturdy glass helps keep drinks hot but still cool to the touch. La Rochere is the oldest glassworks factory in France and produces an exceptional quality glass that is both crystal clear, durable and dishwasher safe. A pressure seam may be visible which is the mark left by the mold in which the glass is pressed. It is the characteristic of pressed machine glass making each item a piece of French glass history.