You can use a platinum diamond pen for the college entrance examination. According to the examination documents, as long as the pen used in the college entrance examination is a pen with black handwriting or a signature pen, the thickness of strokes does not affect the scanning effect, and the platinum diamond pen meets this requirement. However, it is recommended to choose a black carbon pen with a refill thickness of 0.5mm, and it is best to choose a pen that you are used to at ordinary times, so that you can have a familiar feel. Good luck in the college entrance examination, come on!