While there has been considerable investigation on the image stability (fade and yellowing) of digitally printed materials, there has been significantly less evaluation of their physical integrity. This is surprising given that an IPI survey of libraries, archives, and museums showed that abrasion and scratch were the number one reported form of damage to digital prints in cultural heritage collections.
It is a part of IPI’s mission to disseminate the results of our research to the field of cultural heritage preservation. We do this through a variety of avenues including presentations at conferences and publications in journals. A third way we reach our audience is through participating in the development of ISO (International Organization for Standardization) standards. Many IPI researchers have participated on ISO committees related to the permanence of imaging materials. Currently, IPI veteran, Dr.
Since we began our research into the stability of digitally printed materials in cultural heritage collections in 2007, we have received several examples of adhesive-induced yellowing and bleed of digital prints from the public. Some adhesives initiate harm directly upon application to the print. Figure 1 below shows damage caused by a starch adhesive applied to the back of the image area of the print. The moisture from the paste wicked through the paper fibers to the image side and caused the dye inks to bleed. The image on the left shows the print before the adhesive was applied.
IPI’s first two studies on the preservation of digitally printed materials are complete. Our first project, funded by The Andrew W. Mellon Foundation, focused on understanding the effects of heat, humidity, light, and pollution on these materials. Our second project, funded by the Institute of Museum and Library Services, focused on potentially harmful chemical and physical interactions between digital prints and enclosures, the risk of damage during handling, and the sensitivities of these materials to flood.
Like offset lithography, digital press (DP) is used in production scale printing. A digital press uses electrophotographic technology, with either dry toner or liquid toner as its colorant. Unlike offset lithography, it does not require a physical master, which makes it a versatile, high-speed, print-on-demand production printer.
Blocking is the phenomenon of prints becoming adhered to each other front to back as in a stack, face-to-face as in a photo album or to smooth surfaces in contact with the prints such as glass in frames or plastic sleeves in enclosures. Ferrotyping is similar to blocking, but instead of bonding between prints or to adjacent materials, the softening of the print surface causes the gloss of the print to be degraded.
Printer quality is not just about permanence, but a host of other factors such as image quality, reliability, and cost (of printer as well as ongoing supplies of ink/toner and paper). Some prints of high image quality can have poor permanence and others of low image quality can have high permanence. It’s important to make a list of all the qualities you need in a printer and then do the research to find the printer best suited for your needs.
This video shows inkjet photo paper being tested with a brittleness apparatus after it was subjected to light exposure. We can see the flaking of the ink-receiving layer.
This is video microscopy of an inkjet drop on microporous and polymer papers. The video also demonstrates how different imaging techniques can show different effects.
This video shows what happens when starch adhesive is applied to the inkjet plain paper printed using a dye printer. The video demonstrates starch induced colorant bleed after ten minutes of the application.