The research was a preliminary study that would establish the usefulness of a much more detailed investigation. Included in this report are the most important characteristics observed as well as selected extracts from each of the 23 writers. The preliminary observations of the most noticeable variations caused by fatigue were broken down into three types of observations: the variations of the arrangement of the handwriting; the changes brought to the fundamental strokes; and the introduction of writing errors. The study found that writers with good writing speed and above-average writing skill completed the entire test without important departure from their normal handwriting characteristics. The writers with lower speed and writing skills departed rapidly from their original characteristics as soon as they attempted to improve their writing speed. The result was a rapid tiring of writers with the degeneration of handwriting characteristics to the extent that it may impair it's forensic comparison. Among the handwriting features most likely to be modified by fatigue were the following: departure from writing line, increase in absolute size of writing, increase in the relative size of letters, increase in the length of lower and/or upper strokes, increase in the lateral spacing between letters and words, and a general increase in the speed of writing. 6 references