The real test of an interior door is what happens on the other side of it. Someone takes a call in the next room, a kid finally goes down for a nap, and the door either holds that quiet or gives it away. This Craftsman 3-Panel Shaker Knotty Alder Interior Door Slab holds it. Up close, three flat Shaker panels sit inside crisp square rails, and the dark, open knots and grain of real alder run the full face, so no two doors come out alike. Nothing hollow sits inside. Solid knotty alder runs edge to edge at a full 1-3/8 in. thick, which is the heft you feel on the first swing and the mass that soaks up sound between rooms. Doweled stile-and-rail joints keep the slab square and flat, so it still swings true in year five. It ships as a 24 in. x 80 in. slab, with no frame or jamb, and no bore or hinge mortise. Your opening and your hardware set the terms from there. Trim up to 1/2 in. from the sides and top and up to 1 in. off the bottom, then seal the finish you choose on all six sides. A hollow-core slab hangs faster and costs less. Close one, then close this one, and you’ll hear where the money went. Color: Unfinished. Material: Wood.