The act or process of setting type manually. That is, type on a printer is put in place by hand. Handsetting is rare because it is expensive, but it has a distinguished look, which is useful in some contexts.
Aesthetic differences between the original and today's Helvetica can be traced to design modifications that were made to comply with requirements for machine-set typesetting, which replaced handsetting techniques.
However, as machine-set typesetting overtook handsetting techniques, changes were made to the design to simplify production - but at the expense of aesthetic nuances.