We used 3/4 acx plywood for the jig. We decided since we were going to do a lot of scarfing we would practise scarfing the plywood to be used on the jig (not as rigid as LVL but it worked). We ripped the plywood, scarfed the ends. We staggered the scarf joints and glued all pcs to form two 1-1/2 inch thick long planks of wood. After the epoxy cured we cut to desired lengths and assembled jig.