Scutum, wooden shieldboard:
In the Repblic and early-mid Empire the main body of the scutum was constructed of plywood. Three layers of wood glued together with the grains at right angles for added strength. Vertical strips faced the front and the back, while horizontal strips were sandwhiched in between. In the later Empire shioelds were frequently made with vertical wodden planks, rather than plywood. The adhesive used was probably a liquid hide glue. The resulting thickness of the plywood was roughly 1/4 to 3/8 inches. Birch and oak were frequently used woods. Presumably because they are less likely to splinter when struck. The outer and inner surface were covered with painted cloth (linnen, felt, canvas) or leather.