Thanks for the additional info from SteveEisenberg... I tried to hunt down the article itself but don't have the uni library access so not possible... The abstract had insufficient detail to be useful but I find the devices used to be quite amusing considering all the complaints concerning the PRS-600 with its acknowledged poorer viewing than earlier and later eInk devices due to its resistive touchscreen. I still have a 600 but very rarely use it as I find that any extended usage is uncomfortable... just like using an LCD...