As programs evolve they become harder to maintain as the source code becomes more difficult to comprehend. One aspect of comprehensibility is related to the programming style exhibited by the program. However, as this aspect itself is changed during the maintenance process we must attempt to maintain the original programming style quality to maintain the comprehensibility of the program. This paper presents the initial findings of an investigation of how one area of programming style (typographical style), changes over the lifetime of a program. The aim is to draw upon these findings to indicate how typographical style should be measured, and where necessary changed, to ensure program comprehensibility.