Tutorial Cartography for Map Figures in Academic Journals & Books

We still haven't made a map yet. We need to know what the publisher specifications (specs) are before we start anything else. There's no point in creating a beautiful map at full page size when you won't be able to use it in the final product. Publisher specs are often rather restrictive. This will drive much of your creativity but also provide a decent amount of frustration. Be prepared. Additionally, if you submit art that doesn't follow the publisher specs, the art staff may alter your file. This is something to avoid as much as possible for maps because the art staff won't necessarily understand some of the subtleties like how resizing a map would alter it's scale bar or that cartographers can get very picky about label placement.

Let's look at one real-world example: Nature's Journals

I look for the following pieces of information:

1. Maximum figure size: 89 mm (spans 1 column) or 183 mm (spans 2 columns) wide and maximum 247 mm high. This means our figures should be one of the two width dimensions and not a variation. We can have whatever height we need up to the maxium.
2. Aspect ratio restrictions: none listed. That's fine because we have very specific dimensions.
3. Color guidance or restrictions: Color figures have a monetary charge in Nature's journals; uses four-color reproduction (they use cyan, magenta, yellow, and black (CMYK) inks for printed material). If they charge for color, try to make a grayscale map.
4. Font guidance or restrictions: none listed for maps. Some journals will specify a particular font or that the font must be an open font. I suggest sticking with something fairly common unless you really need a special font.
5. Format and quality: electronic format, suggesting .JPG "at good enough quality to be assessed by referees". Eventually, you'll submit higher quality figures for publication but not for the review process. Some journals will specify things like .eps files or .tiff of a certain dpi and may also expect certain color encoding (CMYK, RGB, etc.). For images, if dpi is not specified, I will usually use 600 dpi. Note that if you can't supply a .eps file, a plain .svg is usually readable by Adobe Illustrator with minimal issues.
6. Other limitations: Nature dos not want figures to have separate panels within the same figure unless they are related to each other. This means we can only have one map per figure unless they are related.

Often you will need to piece together specs for maps from different sections of the author instructions. Parts of the figure specs, photography, or graphs may apply.