From The Standard, Volume 5, 2015, courtesy of Sappi North America.
(For other glossaries related to this chapter, go to Bindery Terms or Varnish & Coating Terms.)
Beveled Emboss • The sides of an embossing or debossing die are typically given beveled edges to allow printers to press harder into the paper and get a deeper impression without breaking the paper fiber.
Blind Emboss • This is an image embossed into paper using heat, pressure and a die, but no ink or foil. The result is a raised dimensional image.
Cast-and-Cure • Cast-and-cure is a holographic effect that uses a polypropylene film embedded with a nano-embossed pattern that is pressed into a wet UV coating and cured by a UV light source. After curing, the reusable film is removed from the substrate, leaving behind a holographic effect.
Emboss/Deboss • The process for emboss and deboss is the same. Emboss is a technique used to create a raised impression on the surface of material such as paper, vinyl and leather. Deboss leaves a depressed surface impression. Both require a metal die and a corresponding counter die. Copper and magnesium are soft metals and are used for short runs, but not suitable for complex multilevel impressions or long press runs. Brass is an exceptionally hard metal that can handle multilevel dies and detailed designs and can withstand long press runs.
Engraving • Contemporary engraving is a process in which artwork is chemically etched onto a copper plate. The plate is coated with ink filling the incised spaces and then pressed onto paper, leaving the ink slightly raised on the sheet.
Flocking • Flocking is the application of fine natural or synthetic particles to an adhesive surface. Like thermographic printing, the fibers stick to the adhesive area and the rest is vacuumed away.
Foil Stamping • Foil stamping is a heat-stamp process of transferring a pigment, clear foil or metallic foil, such as gold or silver, onto a substrate. It can be combined with embossing to create a more dimensional image.
Fluorescent Ink • Fluorescent inks have a phosphorescent pigment that works by adding brightness and luminosity to the ink. The ink seems to glow, creating a psychedelic effect.
High-Key Colors • High-key colors are the tints and middle tones at the light end of the color scale. They usually convey a soft, even, harmonious look with little contrast between light and dark areas of an image.
Holographic Foil • A holographic foil is different from gold or silver foil. It has a three-dimensional look created through the use of a special type of photographic plate and a laser light source.
Horizontal Line Screen (a/k/a straight line screen) • Once a characteristic of graphic high-contrast black-and-white Kodalith film for printing, horizontal and vertical line screens are simulated today using a software filter.
Ink Substitution • Ink substitution of one of the CMYK colors in four-color process printing is a way to heighten or alter color impact without the need for more costly touch plates. Typically, this involves substituting cyan, magenta or yellow with a match color that is close in range. For instance, using a chrome yellow instead of process yellow can add drama and warmth to an image.
Laser Die-Cut • Instead of using a metal die to cut a substrate such as paper, this process uses a laser beam to precisely burn or vaporize the sheet to create highly detailed images that are too complex to do with traditional dies. Note: This process can singe the edges where the laser burns through.
Lenticular • This is a printing technology in which a lenticular lens is used to produce an image with an illusion of depth, or the ability to change or move as the image is viewed from different angles. The process requires having multiple digital images, which are then interlaced using a special software to interact with the lenticular lens and produce the desired effect when printed.
Metallic Ink • This ink contains powdered metallic bits, combined with colored pigments, suspended in an emulsion to simulate the look of metal.
Mirafoil, Liquid Foil, Super Silver • This metallic, UV-cured coating, used to create a foil- or chrome-like finish, goes by many names—Mirafoil, Liquid Foil, and Super Silver. Essentially it is mixed like an ink but looks like a foil when dry, and it is applied inline.
Pearlescent Coating • Pearlescent coatings or pigments are used to add luster and iridescence to an image.
Phosphorescent Coating • Phosphorescent coatings essentially absorb daylight and glow in the dark.
Raised Coating • A special flexible plate is required to create a raised coating, similar to thermography. Raised coatings are primarily used to add a dimensional quality to fine details and large flat areas.
Reticulation Effect • A wrinkled look created by increasing the viscosity of the coating to a point where it cannot be spread evenly onto the paper. The surface semi-rejects the coating film, causing it to bead, leaving a granulated look.
Sandpaper Coating • Grainy particles are suspended in coating to create a tactile sandpaper texture.
Scented Coating • Often called “scratch ‘n sniff,” this technique involves scents microencapsulated in pigments that are added to coating and applied to the sheet. When rubbed, the microcapsules break, releasing the aroma.
Sculpted Emboss • Sculpted embossing requires a multilevel die that will accept shapes, angles and edges and produces a slightly carved effect.
Simulated Split Fountain • Split fountain is a way to get a multicolor look using just two inks. This involves putting two colors side-by-side in the same ink fountain on press and printing them off the same plate. The ink colors on the outer edges stay distinct but blend into a third color in the center where they meet. A simulated split fountain can achieve the same look as a split fountain but allows for consistency from sheet to sheet and doesn’t require constant wash-up of the cylinders to keep the inks from getting too muddy.
Soft-Touch Coating • This special-effects coating imparts a unique rubbery to suede-like feel with a matte appearance. It can be applied inline through the coating tower and does not require any secondary or offline treatment.
Spectrum Silver Foil • This is a foil that contains pigments that change color when moved in the light.
Strike Through (a/k/a contrast varnish) • This is a method of simulating a perfect image trap by taking advantage of the chemical reaction between varnish and coatings. A dull varnish is first put down in the area intended to stay matte, then an overall flood gloss coating is applied. The gloss coating is “neutralized” in the varnished areas, which remain dull while the rest of the image goes glossy.
Switch Coating • Switch coating is a UV-based coating that provides an iridescent color transformation effect when applied onto a substrate. Microparticles suspended in the coating refract light, allowing the coating to change from one color to another.
Thermochromatic Coating • This is a reaction caused by dyes that are heat sensitive. The heat from a finger will cause the color to change.
Thermography • This is a printing technique that results in a look similar to engraving but does so more economically. First, the ink is printed on the sheet and a heat-sensitive polymer powder is spread on top. The excess is vacuumed from non-imaged and dry-ink areas, leaving residue only on the wet ink. Then the sheet is exposed to high heat, fusing the powder and ink together to create a raised effect. Thermography is often called “poor man’s engraving” because of its frequent use for inexpensive business cards and stationery.
Touch Plate • This is a means to add extra color to select areas of an image. A touch plate consists of a plate of special match color outside the traditional cyan, magenta and yellow. It often enhances colors that cannot be created in four-color separations alone.