(1) : Thickness. Refers to the thickness of the paper. The thickness of the paper should be uniform, otherwise it will cause obvious differences in printing.
(2) : tightness. Tightness refers to the porosity or tightness of the paper structure, also known as specific gravity or volume. Tightness is closely related to ink absorption and smoothness. In general, the ink absorption of paper decreases with the increase of tightness, so the paper with high tightness should use oxidized conjunctival drying ink.
(3) : Smoothness. Smoothness refers to the level and smoothness of the surface of the paper. Smoothness determines the closeness of the contact between the paper and the blanket, and obviously, the clarity of the text printed on the paper with poor smoothness will be affected.
(4) : Dust degree. The dust degree refers to the existence of black or non-black spots on the surface of the paper that are different from the color of the paper. In offset printing, the limit on the dust degree is mainly determined by the requirements of the print.
(5) : Water content. Water content refers to the water content of a certain weight of paper, which is balanced with the relative humidity of the environment under normal temperature conditions, also known as moisture content, referred to as moisture. In general, the water content of offset paper is 6 ~ 8? Between. The water content of paper is too high, the tensile strength and surface strength are reduced, the plasticity is enhanced, and the curing of imprinted ink film is delayed. The water content is too low, which is easy to produce electrostatic phenomenon and tends to be brittle and hard. When the water content is not uniform, it will form tight edges, flounces, curls or uneven, and wrinkles and folds will be produced when printing.
(6) : pH. PH refers to the acidic or alkaline nature of the paper (expressed in pH value). The acidity and alkalinity of the paper is an important factor that inhibits or accelerates the drying of the ink or affects the PH value of the wetting solution, and also affects the durability of the print (that is, the ink leg color).
