Volume 1, Number 3
May 1988

Alleged Problems in Use of Alkaline Paper

As part of this Newsletter's advocacy program, a collection is being made of written complaints about alkaline paper and problems in its use, so they can be checked out and the record set straight if possible.

Most of the complaints gathered so far have to do with copiers:

Limp and difficult-to-fold paper (said to be a problem that has now been overcome with newer alkaline papers) Slipperiness and chemical reactions between size distillate and copy machine interior surfaces (only a problem with a specific high-speed copier, the IBM 3800; papers have now been developed that can run in this machine)

Toner and loose fibers spreading over the drum, causing a gray background, in extended copying (attributed to age of machine, poor adjustment, & use of bond paper) A tendency to stick or block, and for the carbon toner not to bond properly all the time

Probably most problems with use of alkaline paper are due to three factors: 1) use of paper not designed for the application, 2) the user's misattribution of difficulties to the pH of the paper, instead of to other less obvious variables, and 3) presence of "bugs" in certain papers after the end of the trial period. It takes time and hard work to optimize all of a paper's characteristics at a new pH because the chemistry is so different.

In the first instance above, limpness may result from inadequate surface sizing with starch. In the second, the machine demanded a lot of the paper, unlike many slower and simpler machines, which will accept almost any offset or bond. In the third type of problem, the bond paper performed all right until several hundred had been run through, when loose fibers accumulated on machine surfaces and spread the toner where it didn't belong. There is less information about the fourth complaint, although inadequate heat and pressure should be ruled out before poor toner bonding is attributed to anything else.

So far only one complaint about printing on alkaline paper has come to light. An article in the Sept.-Oct. Instant Printer by H. C. Roth said that "alkaline and neutral paper used in offset duplicators causes the inks to emulsify, causing scumming and toning. This is because these machines require that the fountain pH be maintained between 5 and 5.5 for best results."

Two nationally known experts in ink/paper problem were consulted about this: William H. Bureau, who used to work for Glatfelter and now has a monthly column in Graphic Arts Monthly; and Nelson R. Eldred, who gives workshops an paper and ink problems in the pressroom for the Graphic Arts Technical Foundation (GATF) in Pittsburgh. Mr. Bureau said there were no problems with printing on alkaline paper. In the early days before neutral sizes were developed, alkaline papers did give trouble, but today they are surface sized and it is no problem. Offset duplicators are just little offset presses, and offset presses have no problem, unless they try to use letterpress paper, which is unsized.

Mr. Eldred said that scumming and toning in offset duplicators should not happen; if it did, it was because the printer was using cheap ink, with free acid in it, or with other shortcomings. It is the printer's job to make the inks and papers compatible--it is the system that matters, not the individual element, whether acidic or alkaline paper is used. Any printer who has a problem can have GATF check it out: Graphic Arts Technical Foundation, 4615 Forbes Ave., Pittsburgh, PA 15213 (412/621-6941).