were used to cut off the gob of molten (elastic) glass as it was being dropped into the mould ready to be pressed -
see picture top left below. Although this is modern production at Fenton, the technique, or the tools have not
changed since the early days of pressed glass.
the blades of the shears were relatively cool, the act of cutting the very hot glass (about 1900 degrees Fahrenheit
at this point) resulted in a fractional cooling and resultant hardening of the surface of the glass at the point
where it was cut. This is the shear mark - also sometimes misleadingly called the sttraw
Skilled glassmakers had several techniques to get rid of
- they could “flip” the gob of glass as it was being
dropped into the mould so the cut edge was not in a prominent position.
- they could hide
the shear mark in the intricacies of the pattern, but if the design had large plain areas then the shear
mark is more easily seen, as in the pictures below. The iridescent surface of Carnival Glass will also
often emphasize the appearance of a shear mark.
- the glass item could also be re-heated
and the shear mark smoothed or “fire-polished” out.
as skill, this could also take more time than might have been available under the pressure to maintain
other photos below show a shear mark on a Fenton Pine Cone plate, from a series of different angles. As
this pattern has a large plain area in its center, the shear mark is clearly visible. It is not a flaw or damage -
but is simply a feature of pressed glass.
Here is a diagram of glassmaker's shears. The dome-shape on the
handle, sometimes called a "stomper" was introduced in the
1950s. It was used to smooth out the shear mark when the hot glass had been dropped into the mould,
immediately before pressing.