E-Ink eReaders are lighter than LCD eReaders typically weighing in at half for the same screen size device. The low weight combined with the small size of the eInk eReader, help to improve the portability of the eReader, for example, making it possible to slip into a pocket or small bag.
How does the E Ink eReader achieve this reduction in weight and size, as compared LCD eReader tablets? .
First, due to the energy efficiency of the E-Ink display resulting in smaller battery capacity required and thus a smaller battery size and weight.
Secondly, E-Ink display is not suitable for displaying color or video (currently). Although this may appear to be drawback, it does have benefit that the device is designed specifically for reading and not distracted by other applications such as video, or game playing, with the consequences of increased processing requirement, increased storage capacity, a more complicated user interface, increased power consumption and increased device weight.
In summary, if you are looking for a device specifically designed to give you the best reading experience and you do not require extra multifunctional capabilities, then E Ink eReaders provide the lightest weight option.