WoodFill filament is a great way to print your model with a unique surface texture that can even be stained. Typically, woodfill filaments are around 70% PLA and 30% wood saw dust however this is manufacturer dependent. During printing, it actually smells like a wood shop and by varying the temperature throughout your print, color variation can be achieved. The results of your prints are very setting specific and woodfill has a tendency to result in stringing.  Note, some woodfill filaments are not wood at all but rather a type of foam resembling wood.