PRINTING WITH METALLIC INKS
PRINTING WITH METALLIC INKS
What are metallic inks?
Metallic inks are formulated with tiny metallic flakes which “leaf” together on the printed surface as the ink dries. This leafing of the metallic flakes creates a brilliant lustre. Aluminium flakes are used for silver and brass flakes are used for gold. The gold shades are varied from reddish gold to yellowish gold by varying the metallic composition of the flake and using different tinted varnishes. PMS 871 to 877 metallic inks are pre-mixed and are formulated to run straight out of the can. and will not tarnish in the can, even after a year on the shelf. PANTONE metallic colours, (PMS 8XXX etc) which involve mixing a basic metallic (usually PMS 874 and 877) with a standard non metallic Pantone base, on the other hand, are very unstable in the can and should be run as soon as possible after being mixed or received. Metallic inks are softer than regular ink. It is formulated his way so that the metallic flakes can “leaf out” on the printing surface to achieve the maximum brilliance
Coated paper with good ink hold-out produces the highest metallic lustre. Smooth, uncoated papers give good results with a slightly lower lustre. Papers with rough surfaces prevent the tiny metallic ink pigment flakes from “leafing” together and much of the metallic effect can be lost.
Metallic inks do not require any special fountain solution. Avoid fountain solutions that contain high amounts of glycerin or glycol. These non evaporating wetting agents can slow down drying. Avoid using Electrostatic fountain solutions.
Ink film thickness
Metallic inks are so opaque that it is easy to run too much ink which can overpower the dampening system. Even experienced press operators can apply too much ink inadvertently in an effort to produce the maximum metallic effect. The best way to prevent this is to start with a light image and bring the ink up so it just covers. Then increase the ink flow one notch and adjust the water so it’s just ahead of the minimum to prevent catch-up.
MOST OFTEN ASKED QUESTIONSABOUT METALLIC INKS
Q: My metallic inks dry fast but sometimes I can rub my finger on the printed copy and the metallic colour will come off on my finger. Why does this happen?
A: Some stocks, particularly cast-coated and clay-coated enamels may sometimes cause the ink varnishes to be drained into the paper coating, leaving the metal pigments on the surface of the stock without enough binder to anchor it firmly to the paper. This condition is called “chalking.” Here are some suggestions on how to eliminate this problem. Keep water to a minimum. Waterlogged inks are more prone to chalking.
Q: Do you have Laser-Safe metallic inks?
A: We do not recommend any metallic inks for use on stationery that is destined to be run through a laser printer or high-speed copier. The metallic flakes that are used to make a metallic gold or silver get their brilliance from the “leafing” of the metallic flakes on the printed sheet. The flakes can peel off the sheet by the heat and pressure of the printer or high speed copier, stick to the fuser roller or drum, leading to costly replacement.
Q: If there are no metallic inks recommended for use in a laser printer or high speed copier, what can I do to satisfy my customer’s needs?
A: Unfortunately, there are not too many things that you can do. One suggestion is that you choose a colour in your PANTONE Colour Formula Guide that looks a little like gold. Check the l20s and 130s in the guide. Although the result will not have the metallic glitter of true metallic, the colour shades are close .Another solution is to try a combination of Tough Tex and metallic ink, although the exact combination should be tested first. The metallic ink should not exceed 45% of the total formula.
Metallic inks do not require special roller washes, however, the metallic flake in the metallic inks are often more difficult to remove than just regular ink. A combination of Van Son’s Easy Street roller deglazer and blanket & roller wash will do a fast, excellent wash-up.
- Clive Harper