In a production by typing task, with extraneous factors (e.g., length) controlled, measures such as latency to initial keystroke as well as mean inter keystroke interval typically vary systematically according to the word’s lexical properties. Conventionally, lexical effects in production tasks get interpreted as evidence of cascaded processing between central and peripheral levels. We compare mean and distribution of keystroke latencies within the same stem as it undergoes affixation in sets such as DEPRESS, DEPRESSION, DEPRESSIVE. Novel is the comparison of stems that differ with respect to number of affixes like SUPER, SUPERIOR, SUPERIORITY. Results provide new insights into the ways in which morphological structure can influence purportedly peripheral motor processing.