Process practice, analysis shows that the original ink is not used, its concentration is constant, but in a single sheet of paper printing ink use, with the consistency and mobility of the variation, the concentration will change. Printing speed, temperature and the size of the fountain solution, etc., can affect the concentration of ink. If the printing process in the layout of water is too large, will also enable single paper printing ink concentration by dilution, the printing ink is light. Visible, ink concentration is the variability of the factors affect the quality of ink, so correct understanding and ink concentration about some situation, take appropriate technical measures for printing, has very important significance to ensure the quality of the printing ink. 

Ink is a hydrophobic colloid, which is composed of pigments, binders, fillers and additives, and other components of the uniform mixture. Pigment is a coloring matter, in the ink play a significant role. It is insoluble in water and can not be dissolved in the link, but it can be evenly dispersed in the material in the link of the colored material, as a powder like solid. The size of the pigment content in the sheet fed printing ink determines the durability and the concentration of the ink, and also influences the drying performance of the ink. Pigment as the main material of the color, the quality of ink, and play a decisive role in the impact. So for printing, only pigment fine particle, oil absorption, the proportion of small, cover small force, strong tinting strength, good stability, little color misregistration, colorful, and has good performance of heat resistance and light resistance and acid and alkali, printing ink in order to obtain better quality effect. According to the properties and chemical composition of the pigment, pigments are divided into two kinds of inorganic pigments and organic pigments. Inorganic pigments, including various metal oxides, chromate, carbonates, sulfates and sulfides, such as aluminum, copper, carbon black, zinc oxide and titanium dioxide belong to the category of inorganic pigment. 

Inorganic pigment with good light resistance, heat resistance, and stronger than the major, hiding power, it is not suitable for the multi-color, high speed printing requirements. Organic pigments including commonly used chromogen pigment and lake pigments. Color pigments are: phthalocyanine pigment, pigment, nitroso azo pigment and pigment reduction etc.. Lake pigments are: basic dyes, azo pigment lake and lake lake and other acid dyes. The vast majority of organic pigments with good tinting strength, small particles, light weight, soft texture, bright color and high concentration, is the main raw material of color ink. Binders is ink in the main part, it is the ink becomes fluid materials, has a certain viscosity, it the powdered pigment solid particle mixing link, and the adhesion of the paint transfer, adhesion on the printing and printing with a gloss. Its color, viscosity, tensile strength, water resistance and drying are important factors affecting the amount of ink performance, it is also an important condition to change the size, liquidity and concentration of ink. The filling material is a small, white powdered solids, so that uniform and well dispersed in binders. Like potassium sulfate, magnesium carbonate, calcium carbonate and aluminum hydroxide are filler, they in the printing ink to role in the regulation of the ink of the ink, consistency and concentration. Ink with pigments, binders, fillers, respectively, to a certain amount of ratio of material processed into finished printing ink, often due to printing condition is different, the original ink dilute thick, shading and drying property does not necessarily have to adapt to various conditions, generally through the use of some additives to adjust, such as anti adhesive, adhesive, the dryness of the oil, light mortar and light oil etc., these additives added to the ink, will change the ink concentration. 

The concentration of ink, its viscosity is large, so the size of ink concentration, determines the extent of ink color. When the concentration of ink, printing on the darker hue; on the contrary, it is too shallow color printing. The relatively small amount of concentration of the sheet fed printing ink in the printing cost of the ink, ink quality is better; instead, relatively small concentration of ink used in printing ink, ink is relatively light. The concentration of ink in the printing area of large size plate products, printing effect is particularly prominent. Visible, ink concentration directly affect the quality of printing products, so in printing fine wire or fine lines of products, generally use a large concentration of ink to India, and printing field layout of the products is suitable for concentration slightly low ink to India. 

Because the ink has "thixotropic" side, when printing the ambient temperature is high, the machine speed, ink heating thinning, the concentration decreased, which requires slightly higher concentration of ink to print, can effectively guarantee the product quality ink. On the other hand, you can choose to use slightly low concentration to printing ink. If the small concentration of ink for color printing or laminated color chart, by increasing the layout Bumo volumes to gain required for printing color, but it is easy to make products occurred at the end of the ills. Based on this situation, ink color printing products generally take to the color appropriate to increase the depth of a point, concentration is suitable for bigger, printing effect is better, and to print anti sticking. In addition, the printing of large area field, the line version or textured version, printing speed corresponding to adjust to slow down a bit, to reduce the printing process of friction coefficient and heat to prevent because the temperature rise too quickly, so that the ink easily thinned liquidity increases caused by concentration decreased, the printing ink becomes shallow defects appeared.