Self-Supporting Cones are the most accurate and easiest to use witness cones available. They provide the same information as Orton Large Cones. The advantage of Self-Supporting cones is that they are the correct height (1 3/4" exposed above the base) and have the 8 degree bending angle built in. They do not require plaques. Self-Supporting cones can be set on any flat surface.
Self Supporting Cones are recommended by glaze and kiln manufacturers to achieve the best results.