In the interest of time (the striking of the new coin was to begin in January 1964), Roberts modified the existing bust of Kennedy he had created for use on the Kennedy medal in the Mint's Presidential series, while Frank Gasparro began modifications to the reverse he had created for the same medal. Both Roberts' and Gasparro's designs had been approved by Kennedy. Roberts had met with Kennedy in person to show him early models of the design; although the President expressed no opinion regarding the depiction, Roberts decided to make some changes after meeting him. After the Mint produced trial strikes, Jacqueline and Robert F. Kennedy were invited to view them. Mrs. Kennedy viewed the designs favorably, but suggested that the hair be altered slightly. It was also suggested that a full or half figure of the president be used instead of the profile, but Roberts noted that there was not enough time to produce an entirely new design because of the project's time constraints, and also that he believed the left profile would give a more attractive appearance.