Whether the paper can use for softcover or hardcover book printing is smooth and of high quality. Depends on the printability of the paper and the requirements for printing on paper are.
The color tone of the paper should be as pure as possible in the same texture. The dustiness of the paper must not exceed the allowable range. Has minimal light transmittance. And guarantee mechanical strength during normal printing. The thickness, tightness, and structural properties of the paper. It should remain the same in the same printing batch. The edge of the paper should be at right angles and the slope error should not exceed ±3mm.
The flatness of the paper determines the printing quality of the printed matter. Embosses on high smooth paper. Can better contact with the layout. Make the ink layer on the printing plate transfer to the paper evenly. Paper with low smoothness. It will be due to the unevenness of the surface during printing. Causes uneven contact between the layout and the paper surface during embossing. The transfer of the ink layer to the paper surface is uneven. If you encounter paper with low smoothness. The pressure during printing can increase during printing. It can make up for the phenomenon of faint imprinting due to its uneven surface.
Ink absorption of paper
the absorption of ink from paper. It depends on the tightness (the size of the void) between the fibers of the paper. When the gaps between paper fibers are small. Due to too little chemical fiber. Affect the role of fiber capillary. This causes the paper to absorb the ink to reduce. If the gaps between paper fibers are too large. Inks and pigments will absorb together due to excessive binder absorption. Make a print softcover book appear through the printing phenomenon.
Elasticity and plasticity of paper
During storage, printing, and other processes of paper. There will be various changes due to the different surrounding environments. As under the action of external force. It changes its shape and size. And when the external force stops, the paper returns to its original shape and size. This deformation process calls sensitive elastic deformation. When the paper is subject to an external force, it changes its shape and size within a certain period of time. When the external force ceases to act, It is slow to return to its original shape and size. This deformation process calls a-elastic deformation. When the external force cancels. Paper remains in a state of shape and size deformation caused by an external force, called plastic deformation. Sensitive elastic deformation and hysteretic deformation are reversible deformations. Plastic deformation is an irreversible deformation.
Surface strength of paper
The surface strength of paper. Determines the wear resistance, anti-dusting, and anti-fluffing of the paper surface during printing. Which has a decisive influence. To get clearer dots when printing. Will use some inks with higher viscosity. If the surface strength of the paper is not enough. It will be easy to lose powder and hair loss. And adhere to the surface of the plate. If using lower-viscosity inks. In lithographic printing, it will emulsify with ink and fountain solution. As a result, the blank areas of the printing plate stain.
The moisture content of the paper
The moisture content of the paper affects the quality of printed matter. Too much moisture will reduce the strength of the paper. Under the action of an external force, the paper fibers will pull out. Enhance plastic deformation. Affects the drying speed of the blot. If the moisture content is too little, the paper will become brittle. It is easy to cause damage, generate static electricity, etc. The moisture content of the paper. Has a great correlation with the surrounding environment. Thus, the humidity and temperature of the printing machine room must arrange. To maintain the balance of paper moisture content.