One Extra Large Tree Slice Basswood. This natural basswood tree slice with bark is kiln dried and comes with a very smooth finish. The wood slice is not chemically treated in any way. The tree slab is sanded on both sides and measures 5/8" thick, and will range between 11in-18in wide. Because the tree slice is a natural item, each is unique and will vary in size, shape, and appearance. All slices are at least 11" wide at the narrowest point.