I try to be as spiffy as the next guy: the car waxed, the glass table gleaming. I'm accustomed to seeing the ol' reflection (at least on a good day) and try to bypass providing the opportunity for certain jokesters to spell out "wash me" on the hood. But I know that achieving this polished perfection requires certain knowledge. For example, I know better-now, because of a childhood story that won't be told-than to use the wrong product in the wrong way. Car wax on the table? Glass cleaner on the car? Disaster lurks.
The same is true when using varnishes and waxes prior to finishing printed material. Disaster can lurk, but it doesn't have to. Instead, with many finishing and binding processes, the wise printer consults with the bindery in advance to avoid any glitches. With that in mind, I thought a few reminders might help us all.
Mylar. As I've mentioned before (see my June 1996 column), tabs are nifty little devices to organize reference books, directories and loose-leaf binders for ready access. We probably all use them routinely, sometime even to the point that they become frayed and torn. To protect tabs from frequent handling damage, a transparent or colored mylar is frequently used as reinforcement.
But remember, the automated application of mylar involves 330-degree heat. So types and use of ink and paper should be considered before printing is begun. Non-heat resistant or rubber-based ink may smear when mylar is applied, resulting in unreadable tabs. Use ink that is free of paraffin waxes, silicones or other slip additives. Also, make sure that sheets are dry; a little cobalt dryer in the ink can help with this.
Mylar can be applied to uncoated and coated stocks, but special attention must be given to sheets that have flood coating. Coated stocks can trap air, creating bubbles that ruin the tabs' appearance. Porous stocks are the best choice, with uncoated 90# and 110# index stocks being the most common.
UV Coating. Use of UV coating has ballooned over the last decade because it has a much higher gloss than either water- or solvent-based coatings and doesn't present the pollution and flammability problems of the latter. It is also highly durable and scratch-resistant. Another advantage is its rapid drying time. Passed under short-wavelength ultraviolet light (hence the name), UV coating cures in seconds, dramatically shortening production times.
And designers love it. UV coating makes images pop, helps turn those photos or graphics into real attention grabbers. That's a big reason it is used on a large percentage of paperback book covers, on trading and greeting cards, on posters, magazine covers, brochures, catalog covers, calendars, folders, direct mail pieces and various other promotional materials.
But UV coating also comes with its own set of warnings. UV coating's deep, mirror-like finish shows fingerprints when applied over dark, solid colors. Problems also occur if UV coating is applied over offset powders; the surface of the sheet may end up with the texture of sandpaper. If a spray powder is necessary, make it a small particle (30-50 micron) powder and use the least amount possible.
Inks, too, must be considered. Before being coated, conventional inks need 24 hours to dry, or glossback, a decrease in the surface gloss, may occur. As in tabbing, conventional inks need to be free of waxes, anti-oxidants and mineral oils, or the UV coating will have an "orange peel" appearance and its scuff resistance will be reduced. In addition, the silicone content of the ink must be considered. A high level of silicone will cause poor adhesion between the ink and UV coating, a condition of uneven coverage known as reticulation. Finally, every effort should be made to stay away from Rhodamine red, Reflex blue and Pantone purple. Because these pigments are alkaline-based, they will cause bleaching wherever UV coating is applied.
Also, UV coating, as with all varnishes of any sort, affect further finishing procedures, especially in the case of products that require gluing. Presentations folders are a perfect example. Too often, where we need to apply glue to the pocket, the surface has been coated or varnished, which can cause major problems. Remember to knock out areas to which glue will be applied. And while I'm at it, here is one last reminder related to UV coating: if foil stamping is involved, do that first, then UV coat, then score and then trim.
The Big Rule. Obviously, with any type of coating at any step in the process, the importance of advance planning and consultation with your finishing house is vital. Forethought will save a sizable amount of money, time and angst.
Now, about that childhood story, maybe I will tell . . . ah, but there's the phone. Saved again.
Milt Vine is president of Seattle Bindery, a post-production house specializing in
custom index tabbing in addition to bindery services including plastic spiral, Wire-O®
and perfect binding; folding; stitching; scoring; perforating and trimming services for
the trade. You can reach Milt at 206/682-2558.
©1997, Seattle Bindery.