According to J.T. Marsh, in An
Introduction to Textile Finishing (1951) calendering
"is an important branch of the finishing of cotton,
linen, rayon, and silk material..."
"The chief essentials in calendering are
the moisture present in the cloth at the moment of
calendering, the composition, number, and arrangement of
the bowls, together with their pressure and temperature.
The bowls may be made of metal or of compressed material
such as cotton or paper; the degree of hardness depends
on the particular finish for which the bowl is intended.
The metal bowls are usually made of chilled iron with a
hard, highly-polished surface; these bowls are generally
hollow, so that they may be heated, but very often the
bottom bowls are made of close-grained cast iron..." "Calenders
are made in many different forms, with from two to
eleven bowls, and may be adapted to perform various
finishing operations; some of the larger calenders are
fitted with the necessary devices for utilising only a
certain number of the available bowls..."
"Friction calendering, however, gives a
higher gloss and a greater closing of the yarns; it is
produced by bringing the cloth into contact with a
heated, polished, chilled-iron bowl which is travelling
at a faster speed than the cloth itself...."
I believe that in this case, "bowl"
could be translated as roller.
During the hard press, I use a very
heavy iron (when I can - I'm looking for an old
fashioned steam/boiler tailor's iron weighing in at
about 5 to 7 pounds if anyone knows of one I can buy)
and press directly onto the cloth. No I don't use a
pressing cloth. Yes, I do stroke the iron across the
cloth (depending on the type of cloth and what needs to
be done to appropriately flatten it). If I don't want
the resulting sheen on a wool fabric, a simple steaming
will remove it.
For one of the samples for the Guild of
Canadian Weavers newsletter, I rolled the fabric around
a large pvc pipe, then sat on it and rocked back and
forth to flatten it. I still had to give it a hard steam
press to get it sufficiently flattened to be used for
sewing a garment.
In Sweden, I saw the "old fashioned"
mangles which were basically a large dowel (3"?) and a
flat board with a handle. The fabric is rolled around
the dowel, and the flat board is pressed down onto the
dowel with cloth. With a rocking motion, you roll the
dowel back and forth under pressure. This is actual
quite effective for smaller pieces.
Mangling isn't the same as calendering,
but more accessible for handweavers to accomplish than
actual calendering. For a more detailed explanation
of mangling, please see the article &qupt;Mangling" by
Kerstin Froberg in this section.