I did some contract work for an automatic player
piano company. They use lots of felt to quiet the
mechanisms. Different custom die cut shapes, densities,
and thicknesses.

I cannot remember which company but there is a felt
company in LA that had a catalog that had more types
and shapes than I ever dreamed were possible.

I see 3 in Google, give them a call:

General Felt Industries Incorporated
8320 Rex Rd
Pico Rivera, CA 90660
(562) 948-1432

Western Felt & Fiber
323 S Date Ave
Alhambra, CA 91803
(714) 972-2820?
(626) 281-6300

Acme Felt Works
6500 Stanford Ave
Los Angeles, CA 90001
(323) 752-3778


-Chris
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