Back in Black: The Pain of Fingerprints

I recently had a visit from a surfer looking for info on fingerprinting of black ink. So, here are my thoughts on the subject, in an effort to answer as many questions as my anonymous visitor may have.

Everything Gets Fingerprints
Our hands are oily, no matter how much you wash your hands or how dry you say they get in the winter. Your hands make oils that carry dirt, and transfer it to the printed materials we hold. So, making a printed piece that resists showing these fingerprints can be difficult, when you have some very specific brand guidelines or effects you'd like to achieve.

Back in Black, and Metallic Mayhem
Black and metallic inks are the biggest perpetrators of the fingerprint problem. Gold (PMS 876), silver (PMS 877), and their many-colored kin are very likely to show darker smudges where fingers have been. Black, as well, will appear darker where fingers have left their beasty little marks. After one handling by one handler, a piece with low fingerprint resistance will look like it came from under the french fries at the local fast food joint.

The fingerprint issue is related, I believe, to the shine you desire to buff into your car. A black car looks great with an even coat of wax all over, as it shines the brightest reflections, and shows the deepest shadows.

Likewise, oiled wood (imagine ebony for this purpose) gains a far deeper luster than if it stays "dry." I think these principles apply to the black ink as well.

When you touch the black ink on paper, your skin's oil acts as a polish, or mineral oil for the paper. It sinks in and leaves a lusterous coat on top, which reflects light highlights and deepens shadows. Thus, the black looks darker. For comparison, a white or other lighter-colored car doesn't look all that much richer with a shine, similar to other printing ink colors.

For metallics, I believe the issue to be similar, though there's another factor at play. Metallic inks are part ink, part metallic particles in suspension. When the ink is printed on the paper, the medium (the ink color and liquid) sinks into the paper a bit, leaving an even coat of adhered shiny particles on the paper surface. That's where the shine comes from.

So if you touch the metallic ink on paper, you are not only touching ink, but shiny particles as well. And you transfer your fingers' oils to them. In this case, they deaden the shine of the metallic particles, and the smudge shows as darker and less shiny. Confusing, I know.

Coping with the Conflict
There are several ways to defeat the fingerprint issue, some work better than others, and none are fool-proof. You'll need to decide if coated or uncoated paper will work best for your project and weigh the benefits and disadvantages of them with the desire to reduce fingerprints.

• Print on uncoated paper: Black and metallics don't show fingerprints as readily on an uncoated paper. Metallic will perform worse than black in this regard.
• Coat it: If you're printing on uncoated paper, an additional step you should be required to do is to coat the paper with a flood of varnish. This goes on after printing, and doesn't appreciably affect the touch and qualities of the printed uncoated paper/ink.
  
  If you're printing on coated paper, you can put a varnish on top, but that really has not proven to work great for me. An aqueous flood may perform better, but you need to think about the effect you are trying to achieve. I've always seen better results from a satin or matte aqueous than from a gloss aqueous on top of black or metallic. You make the tradeoff that the black won't look as deep and the metallic won't be as shiny with a matte or satin aqueous. I've had pretty good success with large areas of metallic coverage that are coated with matte aqueous.
• Laminate it: You could always laminate the sucker too. This is essentially a layer of plastic-like film that would go on top of the ink and seal it off completely from the elements. Again, gloss lamination will still show fingerprints more than a matte or satin. Unfortunately, nothing is guaranteed with these things.
• Use black paper: Again, nothing is guaranteed, but black paper performs pretty well against fingerprints. This was my solution for making a black marketing folder discussed in a previous post. That worked quite well, and the folders are pretty resistant to fingerprinting, though less so, I believe, than if we'd printed the black. Also, having to work through the fingerprint issue gave me a unique opportunity to work with a paper with a great feel and characteristics that set it apart from other companies' marketing folders. I tend to believe that challenges and limitations make us more creative, and that played out as true in this instance.
• Use texture: Whether you use a black paper or print it, adding variation to the surface of the paper will give the fingerprint less to grab on to, while dispersing the light reflection enough to hide it better than a flat surface. This was the case in another piece I produced, a notebook, which used a laminated, textured black paper. This stuff became so durable after we mounted and wrapped it, that I've never seen a fingerprint on it. Plus, it also is a unique piece with great touch that will stand out among other similar pieces.
• Use patterns: Just like texture will fool you into not seeing fingerprints, pattern will as well. Anything that reduces the visual even tone-ness of the paper surface will hide a fingerprint better than a flat, smooth, even coat of black or metallic.

In Conclusion
I hope I've given you some ideas for defeating fingerprints on black and metallic ink. It's never perfect, so a lot of it comes down to:

1. what level of fingerprinting you are willing to accept, within the framework of what the job requires
2. what your creative vision is for the piece and how willing you are to alter it
3. how creative you are feeling
4. what you level of budget you can/want to commit

Feel free to ask questions and add comments about your fingerprint successes and failures using black or metallic inks below!