I. Appearance quality

外观质量指尘埃、孔洞、针眼、透明点、皱纹、褶子、条痕、网印、毛布痕、斑点、浆疙瘩、云彩花、裂口、色泽不分歧等肉眼能够察看到的缺陷。

Appearance quality refers to the defects that can be observed by naked eyes, such as dust, holes, pinholes, transparent spots, wrinkles, folds, stripes, screen prints, wool marks, spots, serous pimples, clouds, cracks, color and luster.

二、力学性质

2. Mechanical Properties

力学性质又称为机械性质或强度性质，它又分为静态强度和动态强度两种。

Mechanical properties, also known as mechanical properties or strength properties, are divided into static strength and dynamic strength.

1、静态强度是纸张在迟缓受力的状况下所能接受的鼎力，又称为终强度。它包括下面几个质量指标：抗张强度、耐破度、撕裂度、耐折度、挺度等。

1. Static strength is the most acceptable strength of paper under the condition of slow stress, also known as the ultimate strength. It includes the following quality indicators: tensile strength, burst resistance, tear strength, flexure resistance, stiffness and so on.

2、动态强度是指纸张能禁受瞬时冲击的强度，它反映了纸张受力后瞬时扩散的动态状况。动态强度主要包括下面几个指标：拆穿强度、环压强度、紧缩强度等，这是包装用纸和纸板重要的质量指标。

2. Dynamic strength refers to the strength of paper that can withstand instantaneous impact. It reflects the dynamic state of instantaneous diffusion of paper after being stressed. Dynamic strength mainly includes the following indicators: breakdown strength, ring compression strength, compaction strength, etc., which is the most important quality indicators for packaging paper and cardboard.

三、根本物理性质

3. Fundamental Physical Properties

根本物理性质包括纸张的定量、厚度、紧度、平滑度、硬度、松软度、可紧缩性、吸收性等纸张为普遍的性能。

Fundamental physical properties include the most common properties of paper, such as quantity, thickness, tightness, smoothness, hardness, softness, compactness, absorbability and so on.

四、化学性质

IV. CHEMICAL PROPERTIES

纸张的化学性质包括纸张的化学组成、纸张的吸湿性、灰分、施胶度、酸碱性、耐久性。

The chemical properties of paper include its chemical composition, moisture absorption, ash content, sizing degree, acidity and alkalinity, and durability.

五、光学性质

V. Optical Properties

光学性能指白度(亮度)、色泽度、光泽度、透明度、不透明度等。对印刷纸张来说，纸张的光学性能是非常重要的，它直接影响着印刷品的质量。

Optical properties refer to whiteness (brightness), color, gloss, transparency, opacity, etc. For printed paper, the optical properties of paper are very important, which directly affects the quality of printed matter.