Kai Parthy of CC-Products, creator of the Laywoo-D3 wood composite filament, has invented a new material called Laybrick. It can print as a smooth or rough surface similar to sandstone. It can be grinded, painted, dyed and extruded at a layer resolution between 100 and 500 microns.
View the video here
You can purchase LayBrick from our shop here http://3dfilaprint.com/product-category/premium-filaments/