Ash composition (GCR) and background gain (UCA) as the non-coated material opacity and polyporous increases, GCR application may not suitable for all non-coated material users.

• 灰身分替代（GCR）和底色裨益（UCA） 由于否涂布质料不透明性的贬矮和多孔性的增增，GCR搁置或者并不得当所有的否涂布质料用户。