Digital labels are labels produced using some type of electronic technology. This is in contrast to flexographic labels which are run on traditional presses using plates and dies.
Digital label production is growing quickly due to advances in technology that have vastly improved quality while lowering production costs. There are several types of digital label production devices:
Ink Jet Technology
Aqueous – In this process drops of ink are sprayed onto a label stock in order to create graphic and font images. These presses use 4 color process printing (CMYK) to produce a color spectrum. Some devices can also image a label with a PMS match ink color. The image is air dried, usually with some heat added in order to adhere the image to the label stock. This means that the face stock need to be receptive to ink. This is accomplished by either purchasing coated material from the raw material manufacturer or having the label converter apply a primer during the manufacturing process. Not all papers and films are compatible with aqueous printing. Often, the image will then be varnished or laminated in order to provide an additional level of protection and durability.
UV Ink Jet – Using the same process of spraying droplets of ink onto a label face stock, UV ink jet differs from aqueous in that the ink is cured to the face stock by exposure to UV light. This creates a very durable image. Because the image is cured to the sheet, UV printing allows the use of a wider selection of face stocks than aqueous does.
Dry toner – Laser printers use heat and pressure to adhere an image to the label face stock. Typically, a drum is electrically charge to be receptive to the toner. The toner is drawn to the sheet by an opposite electrical charge and the then heated and press to create a fusion to the sheet of paper. These printers use a CMYK process to obtain the spectrum of colors for the final printed image.
Liquid toner – Very similar to the dry toner method above except that the toner is so fine, it reacts more like a liquid. This allows for a somewhat better print image as the toner particles are smaller. Some printers that use liquid toner require face stock that has been previously primed in order for the image to adhere.
Analog Steel Dies – Just like in flexographic printing, many digital labels go through either an in-line or off-line steel die to create the labels final shape. This requires the use of either a solid steel drum die or a magnetic sheet die that is adhered to a magnetic cylinder. Analog dies add to the cost of the label as they need to be tooled to meet the specific die shape and materials used for the label.
Laser Die Cutting – In place of tooling like that noted above, laser die cutters use a concentrated beam of light to cut the label design by drawing it on the sheet and burning a minute amount away. Laser die cutting can be done either in-line as the label is being printed or off-line in a separate operation.