Douglas fir ponderosa pine

Types of Wood. For the most part, chemical modification has been done with relatively few species of wood. Among the softwoods, Douglas-fir, ponderosa pine, and southern pine have been used among the hardwoods, hard maple and birch have been used. It is easy to generalize on the type of wood used and extrapolate information to an untried species with the rationale that if it worked on one it will work on the other. This is a dangerous assumption and more often than not, it is incorrect. 

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