Platen
From Typewriter Wiki
The platen is the printing surface of a typewriter. Most typewriters have platens made of rubber, while some have platens made of cork.
Contents
Maintenance
Many typewriters, particularly those manufactured before the 1950s, will suffer from hard platens. For these, the only long-term solution is to replace the platen rubber with new rubber. Properly recovered platens will have a hardness around Shore A 86.
Temporary solutions exist in the form of rubber softeners, but these tend to be short-lived and damage the platen over time.
[Short and Associates] of New York recovers platens.