Glass Workability

Wherever glass men congregate, they will invariably become involved in a discussion of glass workability. Each of them can spend hours giving examples, from his own experience, of times when the good forming characteristics of glass suddenly worsened for no apparent reason. Such a change is usually characterised by an increase in the tendency to check; however, poor distribution is also often a consequence. Some will have found that an increase in cullet, a change in tonnage, a change in a raw material, or even a change in the weather may have this result.