Tom,
The terms “synclastic” and “anticlastic” are mathematical
descriptions of surfaces. In a synclastic forms [suffix “syn-” from
the Greek, meaning “same”], the X and Y axes of the surface bend in
the same direction, i.e. both go up, down, left, or right. This
gives you a form that is either convex or concave, bowl-like. In
anticlastic forms [suffix “anti-” from the Greek, meaning "against"
or opposing], the X and Y axes bend in opposite directions. The most
common description for this is a saddle form, where one axis fits
around the body of the horse while the other axis sweeps upward to
support the rider. [Mathematically, there are only three possible
forms for a surface: convex, concave, or anticlastic.]
We commonly encounter synclastic forms – bowls, cups, spoons, etc.
– in their pure state, but rarely encounter anticlastic forms used
alone. [Michael Good’s work is the most visible exception.] Heikki
Seppa’s pioneering book Form Emphasis for Metalsmiths provided
inspiration for his students at Washington University in St. Louis
and in many workshops he taught around the world. The book is still
in print and is a wonderful and daunting read. It provided our
modern vocabulary for what Seppa calls “shell forming”. He wanted
his students to explore the possibilities of metal surfaces and
forms independently of any functional goal, so he borrowed heavily
from existing geometric terminology to describe the kinds of shapes
he and his students were making. Betty Helen Longhi did a
presentation at SNAG in St. Louis tracing the influence of Heikki’s
book and teachings in North American metalwork, complete with an
extensive slide presentation of pieces by many artists, some small
enough to be worn and many quite a bit bigger. The Arch in St. Louis
is a shell form, in fact. If you are researching this, I highly
recommend that you contact her and ask about this paper and her
image collection. She, like Michael Good, has worked with Heikki
Seppa; she also teaches excellent shell forming workshops that cover
anticlastic forming.
When you look at metal objects you often see that anticlastic
surfaces and synclastic surfaces can co-exist on the same piece.
Think of the junction between the spout of the teapot and the pot
itself. At that point, their are axes going in opposite directions.
Another commmon example is a ladle or bowl with a pouring spout on
the lip: that little shift on the plane of the ladle is an
anticlast. One of the ways to determine whether a surface is anti-
or synclastic is to see if it will hold water. Only a synclast can
hold water because the axes create some kind of hollow space where
water can pool, although you may have to turn the thing upside-down
to get this to happen. An anticlast cannot contain water regardless
of how you hold it. The transition between these two kinds of
surfaces can be so subtle that you won’t really see it until you
actively look for it – often these transitions are the most
pleasing to both the eye and the hand. This interplay is also a
fabulous playground for design for both functional and sculptural
objects.
There are marked differences in the way metal is moved with hammers
to form synclasts and anticlasts. Synclasts are often formed by
raising, which stretches the middle of the sheet and compresses the
edges. One can also make synclasts by sinking and stretching.
Anticlasts are formed by stretching the edges and compressing the
center of a sheet. This is one reason they are difficult to do well
and take a lot of practice and patience. The techniques that you
need to make anticlasts are really quite different than the ones
that you use for raising. Michael Good uses dies and presses to
create his production series work, although he still does plenty of
hammering.
Anticlastic forms have existed in metalsmithing since we first
manipulated sheet metal with hammers. I think you will find plenty
of examples in ancient work once you look at them in geometric
terms, and once you look for them in the company of synclastic
forms. If, however, you are looking for anticlastic forms used in
isolation, I suspect that you will not find as many, but they are
out there. Bracelets are always worth exploring, as are other
toroidal [doughnut shaped] and torque forms.
If you are researching this in a formal way or for your own
enjoyment, I highly recommend Heikki Seppa’s book because it will
give you clear examples and definitions that will help you in your
search.
Anne Hollerbach