Papers can be clay coated for surface smoothness and opacity giving high quality finishes suitable for high quality printing processes. 要得到適於高質量印刷工藝的高品質加工紙，為了表面平滑度和不透明度的需要，紙上可能塗布白土。
The results showed that fiber coarseness is changed duringbeating,thus greatly affecting the physical properties and opacity of handsheet. 結果表明，打漿能改變纖維的粗度，從而影響手抄片的物理性能和不透明度。
