Heartwood is usually darker in color except in basswood, cottonwood, and much of the yard lumber intended for building construction. All lumber shrinks as it dries during seasoning. This shrinkage causes the distortion commonly referred to as "warp," four general types of which are shown in Figure 1.2. To determine the approximate amount and direction of twist or wind along the edge of a piece of lumber, socalled "winding strips" can be employed, as shown in Figure 1.3. These small straightedges are placed parallel to each other so that by sighting along their top edges the slightest twist in the suriace will be revealed. This lack of stability is more noticeable in flatsawed lumber, where the shrin Fig. i.j. Winding strips. shrink CABINETMAKING age is on the sapwood or bark side, opposite the heartwood side. That is v is customary to keep the heart side on the upper or outside surface of the so that in the event of cupping, a concave rather than a convex face will be si Quartersawed lumber (Figure 1.4 A) shrinks and swells less than the flat; Quartersawed Plainsawed А В Fig. 1.4. Appearance of grain. lumber shown in Figure 1.4 В. In addition it wears more evenly, is less perm to liquids, and does not surfacecheck or split as badly as the flatsawed > Quartersawed lumber is also known as "edgegrain" or "combgrain"; flats lumber is called "plainsawed," "slashcut," or "bastardsawn." Wood for furniture must be thoroughly seasoned before use, for wood cor hundreds of tiny cells that shrink as the moisture leaves their walls, thus ca a change in the overall size of the piece. Therefore, improperly seasoned lu used in furniture construction will cause warping, shrinking, or checking ii various parts of the finished article. Oldtime cabinetmakers would not lay hands to a piece of wood that had not been seasoned in some dry loft for a or more. Air seasoning reduces the moisture content of lumber between 12 and i: cent, which is not sufficiently low for furniture construction. Modern, conti kiln drying will dry the stock to the approximate moisture content that furr will obtain in service-5 to 8 per cent. Since any piece of wood will give с take on sufficient moisture from the surrounding air so that the moisture ii wood and the moisture in the air are in balance, it is obvious that kiln< lumber must be stored in a dry, warm place while it is awaiting construction W hen permitted freedom of choice, the cabinetmaker will select a wood po; mg good working qualities, which he knows will finish nicely. Therefore Mowing table of characteristics or working properties should be used in with the table for finishing to be found in Chapter 5. Certain soft и IО . Lumber comes dressed or surfaced on one side (SiS), two (S2S), or more sides in the following standard dimensions: Standard Dimensions for Lumber Softwood, surfaced (SiS) or (S2S) Thickness 2%2 1У16 15Лб 1% 2% 3% 4% Width 5% 7V2 SY2 9V2 I0V2 Hardwood, rough % Ц.