Jon Arno was a respected author and longtime contributor to Fine Woodworking who passed away on Dec. 1, 2004. Arno liked to call himself a wood technologist, and he relished sharing his incredible range of knowledge about trees and the products they provide. The following is a collection of his posts to the Knots discussion forum, where he regularly shared tips and definitions about the material most dear to woodworkers, the wood. 

Claro walnut
The name claro is Spanish, meaning “clear” with connotations of “lighter” or “brighter,” in the same way it is used to describe lighter colored, natural leaf cigars. The normal Spanish word for walnut is nogal. The first recorded use of the term “claro” with respect to walnut wood that I have been able to find dates to some trees cut in California in the early 1930s. These trees were said to have germinated from European walnuts (Juglans regia) that had been imported from Spain some time in the mid 19th century. In other words, the trees were not European walnut grafted on to one of our native species, but simply Juglans regia (AKA: “English” walnut, “Persian” walnut) that were grown from the nut in California.
Read more

Eastern Poplar
Eastern poplar (Populus deltoides), has a bad reputation for poor in-use stability. It’s a blond, diffuse-porous wood, relatively soft and rather bland figured. It’s a member of the willow family (Salicaceae) and virtually all members of this family have two characteristics that lead to instability; they are fast growing trees that tend to produce a lot of abnormal wood tissue called reaction wood (which has atypical shrinkage properties) and virtually all of these species have very high T/R ratios, meaning the difference between the wood’s radial and tangential shrinkage is quite large (substantially more than 2 to 1.) This high differential causes a great deal of drying stress and the boards tend to cup and twist.
Read more

Camphorwood
Camphorwood belongs to the Laurel family and this family is known for its potent chemistry. Many of its species are irritating to work with and potentially allergenic…or worse. For example, sassafras is also in this family and it contains an oil that has been declared a carcinogen. Perhaps it is when ingested in quantity or over a prolonged period of time…but I think the government goes a little too far in its quest for public warnings.
Read more

Sorting Maples
Even the Forest Products Laboratory has difficulty separating species within the maple genus…But here are some tips that will improve your batting average (at least among our domestic maples.)
Read more

Fruitwoods
The term fruitwood is usually used to refer to the woods of fruit bearing species in the Rose family (Rosaceae). This would include; cherry, apple, pear, peach, plum and a few other lesser known Old World species. The Europeans make better use of their orchard species in cabinetmaking than we do. Most of these Rose family fruitwoods have fine, even texture and good shaping characteristics and are nice cabinetwoods, but (with the exception of our North American black cherry) the species in this family seldom become large enough trees to be of major importance in the commercial lumber industry. The term fruitwood also refers to the color many of these woods develop once they reach their long term patina…which is sort of a soft light tan.
Read more

Find more articles by Jon Arno.

Fine Woodworking Recommended Products

DeWalt 735X Planer

At high speed, the planer works fast and leaves a smooth surface. But the slower, finish speed produces an almost glass-smooth surface. Knife changes are easy.

Buy at Amazon

Ridgid R4331 Planer

Priced nearly $300 less than the DeWalt 735X, the Ridgid R4331 is an excellent value. Its three-knife cutterhead left wonderfully clean surfaces on plainsawn white oak and white pine. It did not perform nearly as well on curly maple as the 735X.

Buy at Amazon

AnchorSeal Log and Lumber End-Grain Sealer

Good for both sealing the end grain of freshly cut logs and boards, this wax prevents end-grain checking and saves material

Buy at Amazon