Disclosed is a process comprising extruding a poly(hydroxyalkanoic acid) (PHA) to produce a first article; thermoforming the first article in a heated mold having a temperature ≧ about 90° C. to produce a second article; and heat treating the second article by holding the second article in the heated mold for less than about 40 seconds to produce a thermoformed article wherein the PHA composition comprises or consists essentially of PHA and 0 to about 4%, based on the weight of the composition, of a nucleator; and the first article is a film or sheet and is partially crystallized.