Damage to Digital Prints by Adhesives

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. The image on the right shows the magenta dye bleed (especially in the area of the face) after the adhesive was applied.

Figure 1: Ink bleed caused by water-based starch adhesive
Before adhesive application	After adhesive application

Other adhesives react with the prints only after a period of time, whether it was just a few months or several years. Figure 2 shows a severely yellowed transfer adhesive after less than three months’ exposure.

Figure 2: Severely yellowed transfer adhesive

This adhesive meets ISO 18902 Imaging materials–Processed imaging materials–Albums, framing and storage materials. While it may be safe for traditional photos, this adhesive may be extremely disfiguring to some digital prints. IPI is currently testing a large number of adhesives on various digital print types to determine the extent of this problem. Results are now available and can be downloaded in PDF format.