|Form Futura LAYWOOD-D3 Filament|
Formfutura claims that objects printed with LAYWOOD-D3 will look and even smell like wood. They also say that interesting effects can be obtained by varying the temperature during printing: the finished material becomes darker as the printing temperature is increased. For example, the maker can simulate the appearance of a tree's growth rings or wood grain.
Check out the video below in which the print is controlled to give the printed object the appearance of growth rings.
Tip of the hat to Fabbaloo for bringing this to our attention.