Italians managed to confuse not only us, but to a large extent themselves too. Opaline is a French glass type and the Italian answer was Opalina vera (true opaline, made by V. Nason among others) and the much cheaper substitute Opalina Fiorentina - made by many producers. It is easy to make as it does not require complicated recipes, and there is an unlimited number of pastel colours. It is just not quite the real thing.