We are all familiar with desktop inkjet printers. Most of us have one, either at the office or at home. However, most people do not know that inkjet technology is becoming more and more popular for the commercial printing presses used to create books, financial records, ephemera, and many other types of hardcopy. Last September 13-16, 2015, IPI attended Graph Expo in Chicago. This major, annual U.S. tradeshow was founded to demonstrate the latest developments in commercial printing technologies and materials. In the recent past, the event focused primarily on advances in electrophotographic on-demand presses, with inkjet taking the backstage, but this year inkjet had clearly come to the fore. There were a larger number of equipment manufacturers, a developing third party ink industry, and a growing number of paper suppliers to fulfill the unique needs of these new presses. But, is this something that libraries and archives should be concerned about?
Prevalence in Collections
While inkjet is rapidly growing as a proportion of commercially printed materials, it is not yet known in what quantities or which formats these objects will take when entering collections. Unfortunately, this may prove to be a very difficult question to answer, as many obstacles stand in the way. First and foremost, the use of inkjet to print periodicals, books, and other types of objects outside of photographs and fine art is not well known and will therefore be unexpected by libraries and archives. If they are not looking for it, how can they count it? Even if they were looking for it, how would they know it when they saw it or name it without the skills for identification or the proper terminology? In addition, most library and archive materials are not cataloged by print process like photographs or fine art prints. This makes a catalog search to determine the proportion of a collection by technology impossible. Therefore the quantity of inkjet books, periodicals, ephemera, etc. that are already in collections just cannot be known at this point.
Inkjet Press History
Inkjet entered the mainstream in 1984 with Hewlett Packard’s first desktop inkjet printer. The device, however, was intended solely for text and included only black dye ink. As time progressed, innovations such as full color, pigment inks, and wide format printing expanded what was possible with inkjet. Then in 2007, the first commercial inkjet press hit the market. It was not quickly adopted, however, as the print quality was still lower than the competing technologies of offset lithography and electrophotography. The two images of the letter “e” below show the pale colors of inkjet vs. the bright colors of offset lithography. For this reason, inkjet press manufacturers initially aimed their sales efforts at what they called the trans-promo market. This included transactional records, such as bank statements, as well as promotional materials, such as direct mail advertising, both of which require only a limited-lifetime. Of course, what cultural institutions save has never been determined by the original intentions for longevity. Over the last decade, though, the issues of quality have all been addressed and now more and more inkjet presses are being installed to fulfill the growing demand. It is being used to print just about everything from advertising to newspapers to books. Inkjet press is clearly not a flash in the pan, but is now an integral part of the commercial printing industry, and as such is guaranteed to produce materials that will eventually fill libraries and archives.
Technology and Materials
In most ways, the inkjet press is just desktop inkjet scaled up to commercial size, but there are a few important differences. Both devices eject inks from nozzles to color the page surface. The desktop uses a reciprocating printed head that travels back and forth across the page as the paper feeds through, while the inkjet press has a page-wide print head that covers the entire sheet’s width allowing for significantly faster printing. So while desktop printers usually output 10-30 pages per minute, the inkjet press can generate thousands of sheets in the same amount of time.
The press papers also vary from those sold for desktop inkjet in office supply stores. Papers designed for inkjet presses have to compete with those used on offset, so they need to come in different weights, from thin to thick, as well as surface textures, from fibrous newsprint to glossy magazine pages. They also need to have these variations in visual and physical traits and still be able to absorb and hold the liquid ink at a high rate of speed. They can’t absorb the ink so deeply that the final product looks pale, or be so smooth and dense that the ink can’t fully penetrate and spreads unintentionally across the face of the sheet. To prevent these problems, paper manufacturers add special chemical treatments or thin coatings to manage how well the ink is absorbed, making sure it stays close to the surface and remains bright while not smearing. Another way to optimize ink adherence is for the printing press to lay down a primer coat on the paper just before the ink is applied. In this process, the primer is only applied where the ink will be applied and not in areas that are to remain white, saving material and therefore costs.
An interesting twist for commercial inkjet is the use of hybrid printing. This is the coupling of multiple printing technologies into a single system, using the strength of each to create the final output. In one approach, all portions of the final object that need to be identical are run on an offset press. The finished sheets or rolls are then transferred to a separate inkjet press where the variable parts of the object are added, making this a two-step printing process. In another approach, inkjet print heads are mounted onto an offset lithographic press directly over the paper as it travels through the printer. So while the static information is being printed in offset, the dynamic variable data is added via inkjet to make each page unique. One of the most common uses of hybrid printing is mass, personalized mailing. For instance, a county library system with multiple branches may wish to send out a request for support to their large number of patrons over a broad geographical area. A basic letter could be printed via offset, while the unique name of each addressee is added in the salutation along with the name and a photo of each recipient’s own local branch, maybe even a ‘thank you’ for past support, and the street address printed on the envelope. This way, patrons receive something that appears created especially for them.
Inkjet Permanence
But back to the question of whether this is something that library and archives should be concerned about. Will these new inkjet-printed objects need a different preservation strategy than existing materials? Data from research suggests the answer to be both yes and no. There is concern because many of the inkjet specialty papers appear prone to yellowing. While discoloration will not usually impact the readability of a document or book, it does degrade the object aesthetically. It is also possible, though not proven, that this sort of discoloration may be an omen of future, more serious decay. The commercial papers can also be of lower quality than used for inkjet photography and fine art, as the mass-printed objects are usually intended for short-term use. They may contain lower quality pulps or unknown quantities of questionable recycled content. Additionally, many of these objects will be printed with inkjet dyes that can be sensitive to light and pollution as well as water, but even those printed with pigment ink can be sensitive to abrasion. Still, both dye and pigment inks have proven to be resistant to fade while in dark storage and so do not need cold storage environments like inkjet photographs and fine art, though cool will be prudent.
The research clearly suggests a need to be wary, yet these materials are so new that only time will tell how truly sensitive they may be to decay and in what ways. Until then, further studies will be helpful, but also feedback from the field as we gain experience with these objects. Unfortunately, there will be no “printed with inkjet” label to alert collection care staff on the origin or nature of the new objects being accessioned. Process identification for modern materials entering libraries and archives should become a routine part of the cataloging process. Stating that the object is simply a book, periodical, or manuscript may not be enough. For these reasons, development of identification skills will be helpful, not only for the individual institution, but the field at large as we start to share our experiences with each other on what is working and what is not. Education and training in this area is, therefore, highly encouraged.