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Font Size at Different Scales

June 30 2010 | 0 comments
Categories: Labeling, Publishing


I'm wondering if there is an equation or rule that says what the appropriate font and font size is for different scale maps? They would be used in different map outputs like web apps, powerpoint slides, animations, desktop.
I would say that these outputs would be affected differently by things like screen real estate and resolution.
Are there any rules or cartographic standards that I should follow?

Mapping Center Answer:

Unfortunatley, no -- no one single source has this info right now.  But we can give you some ideas. 

At the best, on a print map with very high resolution (upo to 2400 dpi) you would be able to use fonts down to about 5 pts (I usually don't go below 6 pts in deference to older map readers who need reading glasses like me!)  Of course, thsi depends on the font -- some are more condensed and some are more open -- the more open the font (by which I mean space within and between the letters), the smaller the size you can use it at.

Using a standard office printer at 300 dpi, 6 pts is the minimum, and 7 or 8 is usually easier on the eye.

For on-screen viewing, the resolution is degraded to 96 dpi.  In this environment, and with the light being projected at the user instead of pigment being laid on paper, you should use fonts that are at least 7 pts for Windows systems (9 on Mac systems).

At the worst, you would be projecting the map, and this really degrades thing.  For these types of maps, I try to use 12 and more often 14 pt font so the text is legible (that is, it can been seen AND understood).

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