Hardwood Record — Veneer & Panel Section 



September 10, 1918 



Pigment Figures in Veneers 



Caused by Deposit of Coloring Matter in the Fibers of the Wood 



|0 SATISFACTORY EXPLANATION has ever 

 been given of the causes which produce the 

 shaded figures in gum and walnut. The figures 

 are due to the irregular deposit of pigments in the fibers 

 of the wood while it is growing, or at least while the trees 

 are still alive; but it is not known why the coloring mat- 

 ter is deposited in a manner so irregular and apparently 

 at haphazard, and yet in a way to produce patterns, no 

 two of which are exactly alike, yet with a general similar- 

 ity visible in all. 



Walnut and gum are the best known woods display- 

 ing figures of that kind, but there are others. No others, 

 however, are of general use in this country. Gum has 

 no figure except that formed by the deposit of pigments; 

 but walnut has that figure and likewise one due to the 

 annual growth rings. It may combine the two in the 

 same piece of wood. But when gum shows any figure 

 it is that formed by pigments or coloring matter which 

 makes some portions lighter or darker than others. 



This figure is not present in all gum and walnut trees, 

 and it is nearly always absent or very pale in young tim- 

 ber. It appears to be a result of age, and not to be a 

 development while the wood is being formed, but a de- 

 posit in the fibers later in life. Usually, the figure is 

 strongest in mature trees, from which fact it may be in- 

 ferred that the deposit of pigment is a secondary process 

 that does not take place until some time, often many 

 years, after the formation of the wood. 



The reason why some trees never have any figure, while 

 others growing in similar situations and under like cir- 

 cumstances possess it in abundance, is a mystery which 

 has not yet been found out. The soil in which the tree 

 grows has been supposed to have something to do with 

 it; yet other trees of the same kind, standing in the same 

 soil, have no figure. Size and age are often given credit 

 for figure of this kind; yet other trees of equal size and 

 age lack it. 



It is possible, by the use of certain chemicals, to bleach 

 out or at least partly destroy the figure on the surface of 

 gum or walnut, seeming to prove that it is due to a color- 

 ing matter acting upon the wood, but not part of the 

 wood substance. 



Gum's figure more nearly resembles Circassian or Eng- 

 lish walnut than the black American walnut. The Ameri 

 can walnut's figure is usually darker, and not infrequently 

 the annual rings are more distinct than those of foreign 

 walnut. Gum may be finished to resemble the Circassian 

 wood in color, and when the figures are well matched, 

 it is often difficult to tell gum from walnut. This is par- 

 ticularly so if the figures are artificially doctored to make 

 those of the two woods look alike. 



The pores of walnut are larger and more conspicuous 

 than those of gum. It is very difficult to see gum's pores 



without the use of a strong magnifying glass, but walnut's 

 are often apparent. If a question arises whether a pol- 

 ished panel is gum or walnut, it is well to examine for 

 pores, as a help in the identification — but as a help only, 

 not as a sure guide. If pores can be seen with the naked 

 eye, the wood is not gum, and so, if it is either gum or 

 walnut, it must be walnut. Pores are pretty hard to 

 imitate well enough to deceive a person fairly well ac- 

 quainted with walnut, although attempts at such imita- 

 tion are sometimes made for the purpose of passing gum 

 for the Circassian wood. If judged by figure alone, one 

 of these woods might be mistaken for the other, but that 

 can hardly happen if both figures and pores are care- 

 fully examined. 



The heartwood of black walnut is darker than the heart 

 of gum, and that feature is generally sufficient to distin- 

 guish one from the other; but the difference in tone of the 

 heart is not quite so marked between gum and Circassian 

 walnut, though as a usual thing this walnut's heart is 

 somewhat darker than that of gum. The surface of a 

 polished panel of Circassian walnut is brighter than that 

 of gum, and a little experience and careful observation 

 ought to enable a person to distinguish these woods by 

 that characteristic alone, but it cannot be done without 

 experience. It is not probable that gum with natural 

 fininsh is ever mistaken for black walnut. The differences 

 are too apparent; but the appearance of the gum might 

 be changed by artificial means so that gum would pass 

 for black walnut. 



It may be noted that there is less disposition now than 

 formerly to pass gum off as some other wood. Before 

 its reputation was well established it was extensively 

 employed in imitations; but it no longer needs to go to 

 market in that way. It is known under its own name, 

 and sold on merit, and it may be said that it has honestly 

 won its title as the most widely used American veneer 

 wood. In quantity, the plain stock greatly exceeds the 

 figured. Each kind has a field of its own. 



The temporary disappearance of Circassian walnut 

 from market, because of the war, and the unprecedented 

 demand for black walnut as propellor blades for air- 

 planes and as stocks for guns, have given gum a new 

 opportunity in the field of figured veneers. 



Circassian walnut is the costliest wood regularly manufactured 

 into veneer in this country. Before the war the cost of good 

 figured logs was approximately $3 1 5 a thousand feet, about three 

 times as much as mahogany. At present little of this walnut is 

 obtainable because of the war, and it is not easy to say how much 

 it would now cost. Ordinarily about half of the veneer output is 

 rotary cut, and half is sliced. Most of the veneer is cut one-thir- 

 tieth of ..n inch or thinner. It is all used as outside or finish, as 

 it is too costly to use in concealed situations. 



