Papers can be clay coated for surface smoothness and opacity giving high quality finishes suitable for high quality printing processes. 要得到适于高质量印刷工艺的高品质加工纸，为了表面平滑度和不透明度的需要，纸上可能涂布白土。
The results showed that fiber coarseness is changed duringbeating,thus greatly affecting the physical properties and opacity of handsheet. 结果表明，打浆能改变纤维的粗度，从而影响手抄片的物理性能和不透明度。
