As every printer knows, a skid of still-wet sheets on the pressroom floor is a pile of paper that can’t turn into a stack of profit until the job is dry enough to be trimmed, folded, finished, and shipped to the customer. That can take time­—and time when nothing other than drying is happening is the opposite of productive in a busy offset plant.

Hence the appeal of instant drying by curing specially formulated inks and coatings with ultraviolet (UV) radiation. There are two ways to do it: with traditional mercury-vapor UV lamps, and with exposure units that use light emitting diodes (LEDs) as the radiation source.

There are also two ways for offset printers to add the capability: by buying a new press fully equipped for UV at the factory or by retrofitting an existing press with either a traditional UV or an LED UV system. This report examines the retrofitting option, starting with an overview of what vendors of UV technologies are hearing from their customers as they ponder stepping into the invisible spotlight of ultraviolet curing.