By the late 1960s, Larry Bell found that the most interesting part of the cubes was where the corners came together. The next logical step was to focus on making big corners, resulting in the Standing Walls. Simpler constructions allowed for a larger scale, and required larger equipment. The vacuum coating machine that he commissioned to be built was completed in 1969. This machine, affectionately called “The Tank,” a cylinder ten feel long and seven feet in diameter, was used to coat the first large panels, and later a variety of other materials. Scale of the glass panels that composed the Standing Walls was primarily based on the practical proportions of Bell’s own body: not much wider than he could reach, higher than he could jump, or heavier than he could lift with the help of one other person.