Two experiments are reported with the aim of determining the effect of pen shape and size on two different types of task: drawing and writing. Experiment 1 attempted to determine the optimum shape and size of shank for ball-point pens used to perform an accurate drawing task. Twenty-seven participants used a total of nine different pens. Drawing performance was measured by having the subjects follow mazes of different size. The dependent variables were drawing movement time and drawing accuracy. The results indicate that the pen with an equivalent diameter of 8mm had the best accuracy during drawing, even though it had the lowest speed. The results confirm the applicability and validity of the Drury tracking model for such a task. Even though users tended to prefer larger pens, their accuracy with such pens tended to be low. In a second experiment, subjects performed a writing task (with no accuracy constraints) and rated their preference for types of pen. An attempt was made to determine the preferred dimensions of ball-point pens for writing in Chinese and English. A total of 36 'bare-bodied' pens and 20 Chinese subjects were used to evaluate the effects of shape, size and weight on time to write a sentence. The Writing Ability, Comfort and an Overall Rating were given by the subjects. The results indicate that the Chinese subjects preferred a circular shaped pen for writing in both languages. A factor analysis showed that speed, comfort and writing ability are independent parameters in pen evaluations.