Originally posted by the Cartographic Design Team on the Ordnance Survey blog.
This is the second installment in our set of blog posts taking a closer look at our Cartographic Design Principles. Last week we shone the light on Understanding of user requirements and this week we turn our attention to Consideration of display format.
Consideration of display format
To achieve maximum clarity a map should be designed from the very beginning with its final display medium in mind. There are numerous output formats for maps and various types of media on which they can be disseminated. Each has its own merits and its own limitations so there needs to be sound consideration and a valid reason for the choice that is made.
Things to consider are the map’s scale and resolution, colour mode (generally RGB for screen and CMYK for print), the size of paper or screen, the type of paper or screen; and interactivity and functionality options.
These considerations may lead to known rules, for example the minimum point size that can be applied to the map’s text in order to still be legible, or the lightest shade of a particular colour that can be perceived on a particular device. When setting such rules one may consider the optimal display or if the user base is varied then a lowest commonly used denominator may be preferred.
Designing multi-scale maps for web and mobile brings a fresh set of cartographic challenges
Designing maps for web and mobile
Traditionally, maps have been printed on paper and this is a great medium for communicating information. It’s also a great way to carry a map when navigating the world around us – paper is lightweight and easy to fold. Obviously, many maps are still paper-based and it retains it’s own merits as a form for publication, but as we all know, smartphones and tablet computers have made maps a ubiquitous part of everyday life.
A cartographer has a different set of challenges when designing maps for web and mobile. The obvious one being the large variety of screen sizes, qualities and resolutions on which the maps may be viewed. There’s often no predicting which devices your user base will have so you must design for all, or at least the most common.
Fortunately, the tools available to cartographers have really matured in the last few years and there are now lots of tools and resources available that take some of the pain out of the design process. There are map design tools that will scale the map’s features based on the screen on which it is being displayed. This is great for map-makers as it means you can concentrate on the all important elements of design that will deliver most value to the user.
Next week we will look at how to create a Clear visual hierarchy within your maps.