craftingTable.addShaped("iron_chestplate", <item:minecraft:iron_chestplate>, [
    [<item:create:iron_sheet>, <item:minecraft:air>, <item:create:iron_sheet>],
    [<item:create:copper_sheet>, <item:create:iron_sheet>, <item:create:copper_sheet>],
    [<item:create:iron_sheet>, <item:create:copper_sheet>, <item:create:iron_sheet>]
]);