Guidelines for Submitting Figures for AAPG Books
How to Maintain Quality
In our printed publications, figures don't always look exactly like the ones the author submitted. Sometimes, quality seems to have deteriorated. Here are a few reasons, and some suggestions to authors to help avoid these problems.
- Rescans don't reproduce cleanly.
- Hard-copy art submissions that previously were scanned or separated for reproduction via offset lithography or for color plotting never reproduce well in reseparating (rescanning). Rescanning separates the original dots into new dots, which generally yield a moiré pattern and/or a weird color.
- To avoid this problem, submit work as original transparencies, photographic prints, or digitized art on computer disk or tape.
- Grey screens often reproduce poorly.
- Many of the figures we receive from authors come off of a laser printer and are thought to be adequate because they are "recent" and have been created precisely for "this volume." If the author uses any percentage of grey in the illustration and prints to a laser printer, we cannot scan unless the line screen is very coarse. This is an unlikely scenario given the improvements in line screen resolution of even the cheapest laser printers, and of course, because it is illogical. One would reason that the better the resolution, the better the illustration looks, and the better it will print. However, that is simply not true.
- Our suggestion: Avoid grey "screens" wherever possible and use patterns instead. If you do use grey screens, make them coarse, and no lighter than 20% & no darker than 70%, and make adjacent screens differ by at least 20%. The same holds for electronic files.
- The range of reproducible color diminishes with each step in the process,
- starting with visible light and going to RGB and then to CMYK (what you see may not be what you can print, i.e., bright fluorescent colors cannot be reproduced in CMYK). Also, many transparencies submitted are duplicates, sometimes several generations removed from the original. Such transparencies look good to the naked eye and through a hand-held slide viewer, but do not look as good through a magnifying glass.
- Remember, the better the quality of the original, the better the quality of the reproduction.
- Improper resolution in drafting is a common problem.
- Many computer draftsmen/geologists work at a resolution of 72 pixels per inch (ppi) and submit their images on disk. This resolution is adequate (and is the default resolution) for RGB CRT imaging, but is woefully inadequate for offset lithography, which recommends a resolution of 266 ppi. An image generated at 72 ppi cannot be successfully "resampled up" to a resolution of 266 ppi. (The possible exception to this is taking a large image at 72 ppi and reducing it in size while increasing resolution. Only moderate success can be expected.)
- The best reproduction can be achieved by drafting at a high resolution, and exporting the art at that resolution. You can't work at a low resolution and change resolution for exporting-- it still doesn't work. The lowest tolerable resolution without too much visible degradation is 150 ppi. The trade-off is that the higher-resolution file requires an exponentially larger file size.
- PICT files often do not translate into the language of electronic publishing.
- Type may move and/or disappear completely in translating, and patterns and tints radically change. Rather than a PICT file we prefer an EPS file (an Encapsulated PostScript file), which works wonders across platforms and application programs. A .TIFF file is the second best thing to an .EPS file.
- Note: a .PS file is pure PostScript language and is almost unusable for us. Also, we recommend that you not save anything in PICT.
- Embedded graphics in Canvas files and Illustrator files can cause problems.
- When we take a Canvas file created in Windows and it includes an embedded scanned image or plotted image, it comes into the Mac Canvas format "speaking in tongues" (it's all there, but jumbled beyond recognition).
- Solution: If you have Canvas files or Adobe Illustrator files with embedded scans or embedded plotted graphs, also provide the original scan and a good, clean print of what the final product should look like.
- Obscure typefaces on maps and charts may not print.
- If we or the service bureau lack that type face, the type will either be bitmapped or Courier will be substituted. Either alternative looks awful.
- Please design your charts and maps using the common families of type, such as Helvetica, Times, or Palatino.
- We all see color differently.
- Also, different lighting conditions affect color. For instance, a color transparency held up to a window looks different from a scanned object on a CRT, which in turn looks different viewed in color-corrected light on a reflective CMYK printed page. It is practically impossible for us all to view each stage of the reproduction process under the same lighting conditions. Even if we could, we would still see differences because our eyes are different (3% of the male and 1% of the female population are chromatically challenged).
- Let us know when an exact color match is critical to a figure.