Martz Memories, by
Pot lids
Finished lidded pots were among the
projects we could submit for examination at grading time. A student’s work would be evaluated on
craftsmanship shown in the pot, its lid, and the harmonious relationship
between the two. A lid should fit its pot within limited tolerances. A sloppy fit could result in “point
deductions.” Our teacher showed us
different ways to lid a pot. One type
could sit flat on the pot rim, but this method called for narrow tolerances
between the pot and the base of the lid that would be allowed to project down
to the inside of the pot. To overcome
this difficulty the lid’s sides could be tapered, and made to fit inside the
pot. In this case, the angles of the lid sides and the pot flange sides needed
to be parallel. Skill was required. To avoid such problems, a lid could be made
to fit over and outside of the perpendicular sides of a pot.
Karl Martz showed and demonstrated the
different methods for us, and left us to select the types we wished to have
examined. All types seemed to have their
own difficult spots. Bisque firing,
glaze coating, glaze thickness, and glost firing all needed to be considered if
the tolerances were within required limits.
We tried to avoid trouble. Some
potters would place the unfired dry lid on the unfired pot and ask for them to
be bisque fired in that position. To
have a pot fired in a cool place and the lid fired a hotter place in the kiln
could cause problems. Since we could
make fine adjustments at the glazing stage, we chose our glazes,
and the thickness of coatings carefully.
The master encouraged us to make lidded
pots functional as well as pleasant to look at.
At exam time we could be sure he would ask, “Does the lid fit?” If he were examining tea-pots, he would ask,
“How does it pour?” Even if we were
showing a mug or a beaker, he would ask, How does it
lip?” As a result, we formed our pottery
shapes with such caveats in mind.
Students were ever looking for
safeguards. Some would throw two lids
for each pot. The lid that seemed to fit
best was the one used at exam time.
However, the point in production sequence that received the most
attention came in measurement of diameters.
Outside calipers were used for the outer measurements, and inside
calipers for the inner. The caliper
scale markings were recorded in case an extra lid or pot had to be made. A few students made do with a simple ruler
for measuring. For most of us, a fit
within the narrow tolerances that Karl required was not easy to obtain. Years later these concerns led me to apply
problem solving ideas. The results led
to another article for Ceramics Monthly.
“Lids that Fit”, was published in September of 1973.
In
1956, I didn’t question Karl’s reasons for requiring such strict tolerances, or
for being fussy about how a tea-pot poured, but looking back, I can see that
these details were important for us, and for him. For him, because the kind of student he
turned out reflected on his teaching.
For us, the difference between the care we took to make a finished
product and the care others took, would often be the difference between being
rated a prize-winner or being rated an also ran. Karl juried ceramic exhibition contests, and
he well knew the details that judges looked for when making awards. He wanted his students to exhibit
prize-winning work. They did.