PMG Winter Meeting – "Characterization of Digital Output Media… Or How to Hit a Moving Target" by Monique Fischer, Feb. 20

During the first day of the meeting, Monique Fischer, senior photograph conservator at the Northeast Document Conservation Center (NEDCC) gave a talk on her research on the characterization of digital output media. In 2010 Fischer was awarded a Getty Conservation Institute (GCI) guest conservation scholar position to conduct this research and although five years have passed since she started this work, the big picture concepts still remain relevant.
As photograph conservators know, many of the challenges associated with the preservation of digital output media are a result of the rapid development of technology and changes in product manufacture; in some cases materials have become obsolete, their formulations have changed, or their product name has changed. Due to these factors, the importance of gathering the “now” information was emphasized in the talk. This “now” information includes the collection of characterization data (type of paper, surface qualities, and component materials) from unused paper samples.
The impetus for this research project came in 2008 when Fischer noticed yellow stain formation on inkjet papers that had not yet been used. The sheets of inkjet paper were left in ambient conditions for about a year, and were only exposed to indoor air pollutants and some light; the uncovered areas of the paper showed signs of the yellow staining. In the talk, she noted other examples of yellow stain formation seen in different brands of inkjet papers: from consultations with artists as well as firsthand with the digital imaging department at NEDCC. In the latter instance, the staining occurred where the non-archival plastic packaging was in contact with the paper, prior to it being unwrapped. An important factor connecting the papers exhibiting yellow stain formation is that all possessed no optical brighteners (OBAs), and it is known that OBAs, a fluorescent component added to improve sheet brightness, may yellow when exposed to light and heat.
The research project had two major objectives: the creation of a digital paper characterization database and material analysis of paper samples. For the database, 241 paper samples were compiled and they are categorized to include: manufacturer and commercial name, thickness and weight, base substrate and composition, surface texture and finish, presence of OBAs, ink compatibility, and type of coating. Out of this, trends were documented, for instance, 81% of photographic inkjet papers contained OBAs, while only 31% of fine art inkjet papers contained OBAs. Additionally, OBAs were found in different layers of the inkjet papers.
Prior to looking at trends, Fischer notes the importance of using proper nomenclature for these materials. Part of her research includes the development of standardized terminology and she has turned to product discussion groups for photographers and practitioners using these different types of materials in order to gain insight on their current use and application. Though it is apparent that due to the proprietary nature of these materials, characterization may prove challenging.
The material analysis was carried out in conjunction with research scientists Dr. Dusan Stulik and Art Kaplan of the GCI. Initially, Fourier transform infrared spectroscopy (FTIR) was applied as a surface only technique, but due to limited sensitivity, minimally-destructive samples were taken. The findings from one type of inkjet paper were discussed, and in this paper sample, polyvinyl acetate (PVA) and a wax-like material as a possible coating and additive, respectively, were found.
Based on this finding, it was concluded that some coatings on inkjet papers may be PVA, a material widely used in many industries including the paper manufacture industry. In conservation, PVA has been documented as a relatively stable resin, and it is used for certain treatments in book conservation. However, it is possible that the stability of the resin is decreased when combined with additives – thus the yellow stain formation could be a result of degradation in the PVA coating. No conclusions were made on what caused the staining. Additional research goals include conducting gas chromatography/mass spectrometry (GC/MS) as a characterization technique.
Though not fully discussed in the talk, during the question and answer session, a question was asked regarding the impact of the printer profile on the stability of the inkjet print. Without hesitation, Fischer stated that the printer profile may have a tremendous impact on image permanence, specifically in color rendering and amount of ink used when using a manufacturer’s recommended printer profile or a custom printer profile. The main takeaway from her answer is that conservators should do their best [through artist interviews/consultations] to document as much information on an inkjet print including: printer profile, printer, type of paper, type of ink, et cetera, as these factors and their, potentially endless, combinations will greatly impact image permanence.