Above that however, I think an industry standard test needs to be in place that rates plasticity by a numerical scale. I was reading the thread about Continental Clay, and the comment was made that no technical information was given for the products. Clay arts is the only trade that I know of that has such lax standards and quality control for products. Kudos to the makers who care enough to at least supply some working information.
Well, with the terrific job industry already does with standards -- e.g., this clay body works well between cones 5 and 10 -- I'm sure they'd do a bang up job with plasticity ratings (-1 if the clay has dried out while sitting on the shelf for over 12 months and +10 if made yesterday and still mushy in the bag). Clay arts doesn't seem to do well with standards (just look at the various glaze books and see the variations in limits for safe and durable glazes or see if there common agreement on what is food-safe, etc.). Mostly because clay arts represent the bottom of the user world and carry none of the impact that large volume consumers (e.g., commercial producers) can demand from manufacturers. In short, we get the left overs, are the last to know when composition of materials change, etc. because we are a marginal percentage of their bottom lines. And, on a customer-by-customer basis, they will make a batch to whatever specs we give them, so those who have specific requirements can get what they want -- for example, Mark C. has his distributor mix half his clay to be softer knowing it will be sitting/aging for six months before he uses that part of the supply. Such a rating may be useful to some potters like yourself who want a specific type of clay body for a specific technique, e.g., crystalline growth, but most would not have any idea of how to use that information. And, as the clay ages, the rating is likely to become outdated and/or no longer precise.
Standards should be reserved for things that affect health, safety; plasticity does not rise to that level of concern where we ask for and submit to regulation.
- Min likes this