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As printing technology has changed, paper has had to keep pace. We've traced its path through the years.

In many ways the history of offset printing is the history of a mad scramble by papermakers to keep up with the developments of the lithographic industry.

Between 1900 and 1949, offset lithography was the red-headed stepchild of the printing industry, which left it without many choices of suitable paper. By the early 1930s, the pressure upon the paper manufacturer to produce coated papers for offset printing had reached the explosion point. Even though there had been some use of coated one-side paper in stone lithography, it was only now, with the introduction of coated two-side paper, that the offset printer found himself really able to compete with the letterpress printer.

Finally, by the end of the decade, economical, machine-coated papers became available and offset lithographers found themselves on equal footing with letterpress operators.

Letterpress Vs. Offset

In 1950, despite continuous improvements, many print shop managers were still electing to run the same types of papers commonly used for letterpress printing as they would for offset.

Though offset printing was slowly on the rise, letterpress still tended to dictate the type of paper used in the shop because of its dominance throughout the industry.

Because of the pressure-sensitive nature of letterpress printing, paper smoothness was perhaps the single most important concern to printers. With offset, though, the main concern related more to the surface and internal bonding strength necessary to withstand the tackier ink films associated with offset lithography.

Nevertheless, despite these differences, during the 1950s the paper used in both methods was either nearly identical or exactly the same.

"Thinking back, I remember that some of the offset products were very similar to the letterpress products. There weren't that many differences," recounts Ray Rabbitt, national sales manager for International Paper. "I know we did get to a point where we wanted to have multifunction paper."

Though that never really happened, eventually, as the professionalism and popularity of offset began to grow, offset printers began to clamor for paper more suitable to the idiosyncrasies of offset lithography.

By the end of the decade, offset lithographers would no longer settle for the compromised quality of letterpress paper, and paper manufacturers were beginning to respond.

Coupled with the development of new platemaking techniques and more highly pigmented inks, improved offset papers—made primarily from bleached sulfite pulp to provide increased opacity—at last became one of the standards for good offset work.

Then, with the benchmark set, the demand for increased detail, snap and brilliance in both monotone and multicolor printing led lithographers to turn to smoother high-gloss, mineral-coated papers for even better results.

Changes For A New Decade

As the 1950s turned into the 1960s, advances in technology conspired with a rise in general printing costs and mailing rates to create the next major development in paper products: lightweight paper.

Once considered too difficult to handle and lacking in sufficient opacity and strength to compete with heavier grades, lightweight paper suddenly began to pop up all over the marketplace.

Now, as price, printing cost and appearance issues came under control, lightweight paper was set to take its place in the widening world of printing paper.

Following the advent of lightweight papers came the development of paper specifically suited to the needs of xerographic copying.

"When the xerographic printing devices came into to play it necessitated slightly different papermaking techniques, like changes to the grades, to allow paper to work smoothly on these copiers," explains Jim Miller, group manager for Georgia-Pacific. "You were trying to adjust for static electricity and curl, and other problems particular to xerographic copying."

Specifically, those requirements are the paper's ability to resist curling due to extreme heat and relentless twisting and bending along the paper path, and high electrical resistivity, to ensure satisfactory runnability and good image quality.

If copier paper has too much moisture it can promote inadequate toner bonding. An insufficient amount of moisture in the sheet can cause excessive static buildup resulting in feed problems.

To ensure the proper level of electrical resistivity the sheet must be manufactured in a way that accepts the static charges necessary to attract toner; but at the same time it must have the ability to lose that charge quickly after toner transfer, so that by the time the copy enters the exit tray, all static is removed.

Eventually, paper manufacturers caught on and began producing paper with additives to help improve resistivity, tighter moisture controls to resist curling and greater dimensional stability to enhance runnability.

Save A Life, Hug A Tree

Beginning in the late 1970s, recycled papers started to arrive on the scene in response to a cluster of environmental problems (including wasted resources, unnecessary pollution and poor solid waste choices). At the time, there were virtually no identifiable recycled papers available for commercial uses.

As the 1970s turned into the 1980s, the market for recycled papers developed and expanded to include chlorine- and tree-free papers. Unfortunately, as the cost of using environmentally-sound paper caught up with the reality of budget concerns, recycled paper use began to fall off dramatically, after a brief revival of interest in the early 1990s.

Lasers And Jets In The Pressroom

Introduced in 1977, the Xerox 9700 electronic printing system was the first xerographic laser printer to reach the market. Although it wasn't until 1984, when the Canon LBP-CX came out, printing an amazing 300 dots per inch, that laser copying really took hold, it would eventually become the standard for high quality, short-run document reproduction.

Technically, laser printers work on the same electrophotographic, toner-based system as xerography, however, requirements for laser printer paper are significantly different.

"First, they offer much improved color density," explains Georgia-Pacific's Miller regarding laser printer papers. "This results from the higher brightness, which provides enhanced contrast of the image to the paper. And the super smooth finish of the paper keeps the toner on the surface of the paper and provides the tactile feel of a high-quality document."

Miller also notes that laser printer paper is typically sold in a heavier 24# weight to provide better opacity and runnability.

Bob Hieronymus, also of Georgia-Pacific, says that the release of products such as the Xerox DocuColor 40 and Canon CLC 1000 have driven up the demand for "premium laser papers." Also, he adds, the introduction of the Xeikon engine and the Indigo digital press has resulted in new paper products.

Finally, ink-jet printing, mainly used for variable data applications, utilizes tiny droplets of highly fluid ink that are given an electric charge to image on paper.

Since their inception, ink-jet printers have been a boon to home and small office printing because of their low cost and ease of use for color printing.

Although ink-jet printers produce a level of print quality above laser printers, one of their primary disadvantages is their reliance on water-soluble inks. Water-soluble inks smudge easily when subjected to moisture and have a tendency to soak into paper, causing blurring, distortion and paper wrinkling.

To combat these problems, paper manufacturers produce specially coated papers to help the ink stay on the surface of the paper while absorbing the water. Furthermore, like most papers, ink-jet stock is treated with some sizing (starch and other additives) to prevent smearing and feathering.

by Allan Martin Kemler