As early as the 13th century, glassworkers were forbidden to move away. Protective measures increased in severity, and only full citizens were permitted to work as glassmakers or apprentices.
وقد ازداد التشدُّد في هذه الاجراءات الاحتياطية ،‏ بحيث مُنع مع الوقت اي شخص من مزاولة هذه المهنة او تعلمها ما لم يكُن احد مواطني مورانو .‏