Unconventional offset printing inks, such as metal ink, anhydrous ink, fluorescent ink and opaque ink, as a design element and the ability to improve internal output, have been more and more welcomed by users.Application And Skills Of Special Ink
When using non-traditional ink for printing, we must keep in mind the unique properties of each ink, so that we can adjust the printing settings according to the specific situation to obtain the best printed matter. Application And Skills Of Special Ink
This paper introduces some tips when using different special inks, and also introduces how to select the correct fountain solution when using non-standard rubber based, oil-based and resin based inks Application And Skills Of Special Ink
Metallic ink
Metal ink is made of thin metal sheets (aluminum sheet is used for silver ink and copper sheet is used for gold ink). When the ink is dry, these sheets form a layer of molded metal foil on the surface of the print. Application And Skills Of Special Ink
When the metal pigment forms a thin layer on the surface of the print, it will produce a high gloss of gold or silver ink layer. If you change the metal sheet component of the ink or the additive of the toner ink, the color range of the golden ink will change from reddish gold to golden yellow.
Metallic gold or silver inks have a long shelf life and will not lose luster even if stored in containers for one year. However, the metal ink in Pantone metal color manual is not very stable, and should be used as soon as possible after purchase or preparation. When preparing metal ink, softer object particles are used. Application And Skills Of Special Ink
Therefore, the metal sheet in the ink can form a thinner metal foil, or spread on the surface of a single substrate as much as possible to obtain the maximum gloss. Application And Skills Of Special Ink
Metal ink has the characteristics of low viscosity, which is suitable for transmission between ink rollers to make the printing process cleaner.Application And Skills Of Special Ink
Coated paper has good performance of absorbing fixed ink, so the ink luster on it is the most bright. Smooth uncoated paper will also get better results, but the gloss decreases slightly. Application And Skills Of Special Ink
The paper with rough surface prevents fine metal ink particles from forming metal foil on the paper surface, thus reducing the printing effect of metal ink.Application And Skills Of Special Ink
Some substrates, especially polished and clay coated Tang porcelain products, do not have enough adhesion to firmly hold the ink on the surface of the substrate, often only absorb the ink blending oil in the ink and leave the particles of metal pigment on the surface.Application And Skills Of Special Ink
This phenomenon known as “pulverization” will cause the metal color to peel off from the substrate surface.Application And Skills Of Special Ink
In order to prevent “pulverization”, the amount of water should be set to the minimum, because ink with high water saturation is more prone to “pulverization”. When printing on the surface of high coated paper or Tang porcelain, an appropriate amount of desiccant should be added to the ink. Application And Skills Of Special Ink
Before printing with gold or silver ink, the surface of the substrate is usually sealed with a conventional oil-based transparent white ink coated with glue. If “pulverization” has occurred, printing another layer of ink on the first surface will often make up for this mistake. Printing inking oil can also overcome pulverization, but this often reduces the luster of metal.Application And Skills Of Special Ink
Tip: for best results, it is recommended to use metal plate instead of electrostatic plate, which can avoid excessive glycerol or ethylene glycol in the fountain solution, because these nonvolatile liquid media will slow down the drying speed.Application And Skills Of Special Ink
The opacity of metal ink will cause the operator to compensate for excessive ink, resulting in ink imbalance. This situation should be avoided as much as possible, because it will bring too much burden to the fountain system, Application And Skills Of Special Ink
resulting in paste (ink particles are emulsified in the fountain solution) and dirty (ink adheres to the non graphic part of the printing plate). Application And Skills Of Special Ink
Even experienced printers have to use too much ink to achieve the most perfect metal effect. The best way to prevent these failures is to add ink to a lighter image so that it just covers the image.Application And Skills Of Special Ink
Then, increase the ink amount and adjust the water supply to make it slightly higher than the minimum value, so as to avoid inking of non graphic parts. During the drying process, the thin metal layer will protrude, providing a brighter luster.Application And Skills Of Special Ink