Roger,
Some hammer felt sheets have tapered thickness and the density of the
felt tapers as well.
Hydrolic presses are most often used, except at steinway, I think.
Felt is not a perfectly homogenous material so there will be hard and
soft spots in any good hammer. Hand cutting is obsolete, Steinway may
still be doing it that way. Renner uses routing machines to form their
felt, Isaac uses an extremely sharp two bladed rail run cutter that cuts
extremely evenly.
As Isaac says, "A cannon ball is hard and a cotton ball is soft. Let's
talk more about the tone we want and ways and means to get that tone.".
Different pianos and different venues will require different power and
tone elements to sound best.
Newton
nhunt@jagat.com
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