I've Got a Little List

Press experts Chuck Blevins and Raymond J. Prince each shared a detailed list of press pointers with their respective NEXPO audiences.

Blevins: Wake Up to the Quality Crisis

During the NEXPO symposium, Are You Prepared for the Future Quality Crisis? Blevins, chief executive officer of the Blevins Harding Group in Vienna, Va., excoriated newspapers for producing poor quality. Blevins listed eight major areas where he believes newspapers miss the mark:

Excessive ruboff, which makes readers want to wash their hands after reading the paper. It typically results from setting water and ink levels too high.
Blurred type, due to trolley and nip marks, that makes readers have to guess at the last four letters of each line. The problem has increased as papers reduce margins to save newsprint.
Substandard papers going out at startup, with images too light or dark to be read. Again, the newsprint-conservation effort is the culprit. Through good maintenance, the first copies off the press should be as good as the last.
Poor registration, which blurs pictures enough to make readers think they need new glasses. It is also advertisers' number-one complaint.
Incorrect ink settings make those Dallas Cowboy uniforms look like the Miami Dolphins'. Color bars or gray bars can help printers set the ink correctly.
Ink setoff to adjacent pages makes readers read through an extra layer of ink. Like ruboff, it occurs when water and ink are set too high.
Paster copies going out lead readers to believe you haven't printed all of the pages because some are blank. This is unpardonable, Blevins said, because newspapers do it knowingly "just to save a few dollars."
Holes in bottom-of-page classified ads, caused by folder pins, often destroy crucial information such as phone numbers in the classifieds.

Prince: Problems in Press Land

As senior technical consultant for the Graphic Arts Technical Foundation, Prince often receives frantic phone calls from pressroom managers. Their problems tend to fall into 20 categories, which Prince described for his NEXPO audience. In order of decreasing frequency, they are

Gear streaks: A regular pattern of streaks caused by incorrect plate-to-blanket or bearer pressure. Solve the first problem by repacking the plate and blanket, the second by adjusting cylinders for correct bearer pressure
Slur: Dots are not round but oval. The problem is caused when a loose blanket slips and is corrected by tightening the blanket with a torque wrench. Torque every blanket the same and never mix brands of blankets. Slurs are often confused with doubles--printing two dots instead of one--which are caused by web weave and can be corrected by changing paper.
Gas or chemical ghosting: A drying ink film affects the drying of a previously printed ink film. This usually results from rushing and can be prevented by allowing more time for the first printed side to dry, adding drier to the ink or using a faster-drying ink.
Mechanical ghosting: Ink form rollers cannot supply enough ink. Use an oscillating form roller, an air curtain (blower) to enhance water evaporation or a take-off bar.
Ink will not dry on sheet: Caused by too much acid in the fountain solution or too much water on the press. Correct the first problem by increasing fountain solution pH to between 4.5 and 5.0, the second by adding alcohol or alcohol substitutes.
Conductivity of fountain solution varies: Often occurs because of inconsistent water supply. The best answer is to use reverse-osmosis water.
Dot gain: While there are 70 causes of dot gain, one study showed that bad ink is the most common. Use an ink with more body and higher tack.
Four-color job will not fit on press: Possible causes are a bad plate frame, poor plate and blanket packing, and varying paper moisture. The plate frame should have a draw-down time of 20 seconds or less and use a tail pin. Plates and blankets should be packed for the correct print length, and paper conditioned to pressroom temperature and humidity prior to printing.
Multicolor ink trapping: Trapping is the ability of one ink to print on top of another. Problems occur when wet ink is printed on wet ink. The sequence, tack, film thickness and/or viscosity of the inks must be adjusted.
Scumming: Ink bonds in the non-image areas of the plate. Lack of moisture on the plate, one of many possible causes, can be corrected by increasing the amount of fountain solution or adjusting the dampening rollers.
Ink in fountain solution: Caused by sloppy roller washing or ink feedback, cured by using a better roller wash or ink filters.
Web fan-out: Caused by uneven tension or moisture content across the web, fixed by using an automatic tensioning system or stochastic screening.
Hickeys: Can be caused by coating particles or dust on the paper and fixed using a web cleaner.
Static in the pressroom: Caused by low moisture, cured by maintaining relative humidity between 40 percent and 50 percent or using static eliminators.
Uneven ink coverage on the sheet: Use a densitometer to measure and help maintain ink densities.
Plate blinding: Replace or remix the fountain solution.
Ink emulsification: Caused by "soupy" ink or excessive dampening, cured by using a higher-tack ink or resetting dampeners.
Proofs do not match press sheet: Ask the ink vendor to match its inks to a standard color-proofing system and correct for dot gain.
Back-trap mottle: Change the ink-laydown sequence from K-C-M-Y to K-M-Y-C.
Matching PMS Colors: Obtain new color books annually and keep them in a dark place to prevent fading. Also, set expectations by getting the customer to OK print samples prior to the run.

TechNews Volume 1, Number 4: July/August 1995