![Task ][1] Many research domains have employed gradually morphing pictures to study perception under ambiguity. Despite their inherent utility there are only a limited number of stimulus sets available, and those sets vary substantially in quality and perceptual complexity. Here we present forty morphing picture series. In all sets line drawings of pictures of common objects morphed over 15 iterations into a completely different object. Objects either morphed from an animate to an inanimate object (or vice versa), or morphed within the animate and inanimate object categories. **Please note that the task is part of the paper *Assessing perceptual change with an ambiguous figures task: Normative data for 40 standard picture sets* currently in press in the journal *Behavioural Research Methods*. If you want to use the picture sets for a publication, please refer to this paper for more details. ** The zip-folder includes all fifteen pictures of all forty picture sets in alphabetic order. Each picture set is included in one morphing direction only (e.g., BaUm01… BaUm15 corresponds to a picture set morphing from a bat to an umbrella). Normative data can be found in the Excel files. Each of those file has a ReadMe sheet in the file, explaining the data. **If you have any questions, please contact us: elisabeth.stoettinger@gmail.com** ![enter image description here][2] [1]: http://artsweb.uwaterloo.ca/~estoetti/task.jpg [2]: http://artsweb.uwaterloo.ca/~estoetti/Table.jpg