Shamefully late to the party, I finally decided to try some Fender 351-shape celluloid picks. Since the thickness in millimiters was not disclosed, all I had to go by was the term “heavy”. Unfortunately, although lovely to look at and really well made (the gold-colored lettering seemed neatly applied, and the edges looked smooth all around), they were thinner than I had expected. I am not so sure I would agree with them being classified as “heavy”. If I had to guess, I would say that they are thinner than a millimeter. This perfectly illustrates the problem with not using precise scientific measurements: all individuals interpret vague adjectives, such as “light”, “medium”, or “heavy”, slightly differently, especially when they differ from one brand to another, and sometimes even from one range of picks to another.