One project in particular, he adds, brings back painful memories. When a protective UV coat was later applied to the cover, an unexpected reaction occurred with the metallic ink and the drying powder, resulting in blotching and streaking during the binding process. Since the books were already bound, Lynx was obliged to reprint all the book pages as well as the covers, this time laying down an aqueous coat before the UV coat was applied. Bill Webber, the owner of Seattle-based Ultrakote, which handled the UV coating of Best's book, wasn't surprised that there were problems. He advises against applying a UV coat to metallic inks but says varnishes don't cause the same problem.
Fluorescents are another category of specialty inks that necessitate careful planning.
Because fluorescents are prone to fading in sunlight more quickly than are ordinary spot colors, a UV coating may be necessary. Unlike metallics, fluorescents work well when substituted for process colors. The results are similar to what you get with Hexachrome printing, although the color gamut isn't as wide as with CMYK or the six Hexachrome inks. You can also use fluorescent bump plates to make certain areas pop. Faith, Hope, and Clarity Many specialty inks can't be produced with CMYK comping and proofing devices.