Color Effect --- the Major Concern for Offset Printing

Printing makes the paper packaging products shine and stand out from the crowds. After printing, the paper boxes and bags become colorful and meaningful with different layers of presentation. Among all the printing, offset printing is very popular for its high printing efficiency. Shopping paper bags, party gift boxes and other paper packaging boxes are often seen with offset printing. However, offset printing also has setback like color aberration. How to control color aberration is a top concern for offset printing. Therefore knowing the factors that could affect color aberration is quite important before controlling them.

Firstly, paper materials could be the factor that influence color effect including paper whiteness, absorbance, glossiness and smoothness. Whiteness is mainly influential to the representation of  colors on the ink layers. Therefore, to make sure of same lot of paper materials manufactured at the same time is quite vital to the color effect caused by whiteness. Different paper absorbance could make a different printing hue and glossiness under same condition. The nature, thickness, evenness of the coating somehow decides the absorbability of the paper material. Therefore, to avoid color aberration, the absorbance state of paper surface should be carefully observed to apply proper ink quantity. The glossiness and smoothness of the paper materials itself determines the printing glossiness and smoothness. The strict quality control of the paper is the original factor to be highly considered.

Secondly, surface treatment of paper materials could affect the color presentation effect. Paper surface treatment for example, laminating, UV printing, coating and stamping is somehow relative to the hue changing either physically or chemically. For instance, physical influence happens when laminating film or UV oil changes the color density;  chemical influence happens when adhesive or other solvent is applied to the surface. Taking this into consideration would help achieve a satisfactory color effect.

And the operation of printing crafts is another major factor for color aberration. The printing speed could make different color darkness by outputting different water feeding quantity. High speed printing generates less water evaporation, while low speed printing generates more, causing unbalance of the water and ink, leading to color aberration. Therefore, a stable printing speed must be ensured. Printing pressure is another factor that should be monitored, for it is one of the conditions for ink transferring. It is not uncommon to have an uneven paper surface for printing, the printing pressure in this case is crucial to the color effect, because with less pressure or uneven pressure, the ink layers would not be delivered perfectly. To have proper printing pressure, the surface of printing plate, rubber blanket, and the paper surface should be well organized to avoid unevenness. 

To avoid color aberration, more actions should be done, for example the routine check and maintenance of the printing equipments to avoid printing failure, and the mixing procedures of the inks should be strictly followed, etc.