Philadelphia Reflections

Modern Printing and Post-Modern Printing

Modern Print Press

There are many more authors than publishers of books. Since almost every school child owns and uses a home computer, this disparity might be even greater except for a technical barrier between home computers and high-speed printing presses in the way they treat illustrations. A presently insurmountable mismatch arose from commercial printing presses migrating from movable type (i.e. Gutenberg style) to page-images, whereas the computer industry aimed for cheap printers which perfected the Gutenberg method instead of replacing it. Commercial printers need to produce high volume output inexpensively, while cheap computer printers produce low-volume output and disregard a rather high unit price. Most of the barriers between the two have been overcome, except for photos and other detailed images. Let's give a simplified explanation.

Since 1993 when Adobe invented the method, commercial printers generally work from what amounts to a photograph of each page, called a PDF or "portable description format". To some extent, portions of a page can be stitched together like a patchwork quilt, but of course, all the pieces must be uniform in their technology. The industry standard is that everything is printed at 300 dots per inch. That's essentially 300 pixels per inch. The establishment of this standard made it possible for huge high-speed presses to produce hundreds of pages of newsprint a minute on machines which cost millions of dollars apiece. Commercial printing during the first half of the Twentieth century accepted the massive cost of the printing machine in order to promote production speed. Home computer printers sacrificed production speed in order to become cheap. Profitability comes from the ink, not the printer.

Low-volume desktop printers can afford to take the time to examine each character or image as it comes along and readjusts appropriately. Essentially, computer printers do individual typesetting every time a new page is printed. They are thus able to exploit considerable compression for storage, or for the speed of electronic transmission for printing at a remote location. For them, 72 dots per inch are sufficient, since computer-driven printers have acquired the facility to guess the gaps between dots (dithering) well enough to fool the eye of the reader. Since the same thing is true of display monitors, there is resistance in the computer industry to sacrificing the interests of the multitude to the needs of those comparatively few authors and publishers who use the mass-printing industry to keep their unit costs low. Computer printing squashes thousands of pixels down to 72 per inch.

But it's hard to convert photo images back from 72 to 300 dpi since the dithering trick won't stretch that far. A good illustration is the washing of wool socks. You can throw argyle socks in a washing machine and they will shrink to the size of baby booties, but they won't stretch back up if you decide to wear them. The usual expedient is to enlarge a small picture and take the second picture of it, then enlarge the enlargement, and so on. Alternatively, the Genuine Fractals program by Altamira Group comes closer to achieving the desired result, but even it has limits. When someone has more than a very few pictures that need stretching between Internet screen display and commercial printers, the current best advice is to store two different-density copies of the same image, and use as required.

Printing Press

Slight re-design of workflow is advised to create still a third version of the image, for the purpose of storage. The biggest possible image with the most pixels possible should be stored on the author or publisher's own computer. A second, shriveled 72-dpi, image is sent to be stored on the host computer of a website and can be used for desktop printing as well. When commercial printing happens to be desired, the much larger stored image can be shriveled to 300 dpi by conversion of a page to PDF format, or else (for editing) this third version of the image is incorporated into Office Word , subsequently re-incorporated back into a pdf file for final printing. The PDF conversion is quick and simple once a decision is made as to what the final product should look like after it is printed. Fine art display or other highly demanding graphics will follow this general outline, as well. Those who have any aspiration for high-density output would be well advised to go back to the original photograph. In 2008, that translates into another maxim for the photographer who takes the original picture: Always take all photos in RAW format, with a view toward later flexibility of use. Less demanding output can be produced from degraded copies of the RAW original, the most common of which is now the so-called JPEG format. Those who discard an original RAW image, are almost always sorry. And those who buy cheaper cameras that go straight to JPEG are just asking for frustration. Now that memory chips have become cheap, the extra technology to generate the RAW image does not greatly increase the cost of a camera, but greatly enhances its ability to retouch images without breaking up in the repeated dithering and re-dithering usually required for retouching. A number of steps in the photography process could be eliminated if the user would accept the requirement of some new step resembling retouching as part of every snapshot.

Originally published: Monday, October 27, 2008; most-recently modified: Friday, May 24, 2019