(a) All quality marks applied to any article shall be equal in size and equally visible, legible, clear, and distinct and no quality mark which is false, deceptive or misleading shall be applied to any article or to any descriptive device therefor. No more than one quality mark shall be applied to any article and such quality mark shall be applied to such article in only one place thereon except as elsewhere in this Act specifically permitted.
     (b) Wherever in this Act provision is made for marking the number of parts or percentage of metals such number or percentage shall refer to weight and not to volume, thickness, or any other basis.