Generally, for your printed pieces you can go as small as 4 or 5 points for black type on a light or white background, 6 points for white type on a dark, black, or complex background (also known as reverse type). This varies depending on the typeface used.
For on-disc printing, we recommend type be no smaller than 6 points, 8 points for reverse type.
For smaller type, such as lyrics and credits, we recommend you use simpler typefaces such as Arial, Helvetica, or Times New Roman. Display faces—the “fancier” fonts with lots of detail, like Vivaldi or Edwardian Script—are designed to be used at large sizes, and can be difficult to read even at 10 points.