ColorFabb wood fill
These are PLA based and basically have sawdust in them. They do three different versions. A basic "wood fill" which is very much the colour of normal MDF and probably just pine; a bamboo fill; and a cork fill.
They are very similar, and print using same settings as PLA. They result is a nice matt finish rather than the more usual shiny finish of PLA. The bamboo and wood fill tend to be a bit "stringy" so leave material in prints that you may need to cut out. The cork fill much less so. The main difference otherwise is the colours, with cork being darkest and wood fill being lightest, and bamboo in the middle. The end result is very much like MDF for the wood fill, and perhaps more like cardboard for the bamboo fill. The cork is darker.
In terms of overhang, the bamboo is better than the cork.
The seem to be very stable with very little shrinkage as printing. They also leave your room smelling of sawdust! You can smell the different materials... Scratch and sniff 3D printing, anyone?
We have one customer specifically asking for wood fill prints as they provide a nice texture and are very stable and precise.
The image shown is of a twist box with one part in bamboo fill and one part in cork fill. It is rather nice.
If you have not tried these, they are materials with which it is well worth experimenting.