Wrong planchet stock is when planchet coil stock intended for another denomination is ran through the blanking press that cuts the blanks into normal diameter as the intended denomination. In other words, in the quarter example above the dime coil stock was fed through a blanking press that was cutting blanks out for quarters. So the diameter is correct but the thickness and weight are not.
Wrong coil stock errors are not always easy to ID but there are some nickels struck on clad dime stock and show the clad layers. This error is often misrepresented to one needs to do their research and have any potential wrong coil stock errors examined by an expert.
The 1970-D Washington Quarter struck on a dime coil stock sold for $36 and the 1955 Lincoln Cent struck on a dime coil stock sold for $1,725.