ReportBuilder uses the Printer device context to perform all calculations required to generate the report pages. This includes measuring text, wrapping text, and calculating the vertical page space required by a stretchable component such as a memo.
Using the Printer device context results in a very high degree of accuracy when printing to the printer. For report Preview, all page elements must be scaled back to the screen. A typical printer has a resolution of 600 pixels per inch (or more). A typical screen has 96 pixels per inch. Thus there is some loss of fidelity in rendering to the screen.
For multi-line text such as memos, ReportBuilder sometimes shrinks the font size for the preview so that the rendered text can fit within the required vertical page space. Even when True Type fonts this is sometimes necessary.