Another economical basket, the tension tray is so called because it is the tension produced by weaving the stiff butt ends of willow rods over and under a hoop and one or two ribs that keeps the basket together. The tray illustrated demonstrates the range of natural colours available in willows, from pale yellow to dark purple and almost black. The same principal of weaving the butt ends of rods in tension is a traditional Catalan way of making the base of a basket.