During an informative presentation, Beau Snider, director of corporate technical services at Wikoff Color, first taught students how inks are made. Pigments, which provide color, are added to a fluid diluent such as water, oil, or solvents. Resins are added to help disperse the pigment, creating a concentrate that is easier to use. Various functional additives like slip aids or defoamers are then added for functional properties. Some types of inks also require drying agents.
Next, Snider explained the difference between process and spot color inks. Process color inks—cyan, magenta, yellow, and black (CMYK)—generally contain one, fairly common pigment. They are widely used, manufactured in large volumes, and are usually low in cost. Spot color inks, on the other hand, are usually specialized blends that contain multiple pigments and sell at a higher price point than process colors. Proprietary logo colors almost are almost always customized spot colors.
Since inks can be manufactured for various purposes, Snider recommended that paperboard packaging manufacturers carefully consider the design at hand when choosing their inks. For example, oil-based inks take about three days to dry completely. Although coatings can allow for quicker use, this drying time must be taken into consideration. Another important factor is tack, or the stickiness of ink. When wet trapping multiple inks, the tackier ink must be applied first; otherwise, the inks will not adhere to one another. Coatings can also be a potential complication, as the same ink can look very different depending on the coating used.
Other considerations include viscosity, color strength, transparency, fade resistance, coatability and scratch resistance.
“Choosing inks isn’t as simple as it might seem,” Snider said. “But if converters gather all of the facts, understand their own design objectives, and rely on their ink supplier where necessary, they will choose the best ink and coating combination for the best folding cartons.”
The next Folding Carton Boot Camp will take place on Dec. 12-13, 2017, and is open to PPC members and non-members alike. For more information, visit paperbox.org/bootcamp.