Labels or names on maps can have multiple functions: to provide a location, to provide identification of features, or to provide other additional information to the user. Names can be proper names such as the official names given to places or they can be descriptive names such as hospital, pub or parking. What labels are included on a map will depend on the requirements of the user and the purpose of the map. When deciding what labels to include, think carefully about what might help the user to understand the message of the map or to orientate themselves in terms of where the area of interest is.
Text design
Text can add meaning to a map and help the user quickly differentiate between different feature types (e.g. rivers vs settlements) or between features of the same feature type (e.g. settlements) but of varying size or importance. This can be achieved by carefully changing the characteristics of the text.
Font and type style
First, the font (or typeface) can be altered e.g. choosing Times New Roman vs Arial vs Verdana. This can affect the general look and feel of your map so it’s worth trying some different ones to see what looks best. You might want to use this to your advantage, for example if you were trying to create an old feeling map. Otherwise, popular fonts are a good place to start – they are popular for a reason. Also think about your display medium, as fonts such as Arial, Geneva and Verdana (sans serif) are more legible on screens. It is however best practice to limit the number of different fonts used to just a few and then vary the size, colour or character spacing to alter the appearance of text rather than using lots of different fonts. Generally, overly ornate fonts should be avoided as they can be difficult to read.
One of the key choices is whether to use a serif or sans serif font (type style). A serif font has decorative strokes at the end of each stem of a letter whilst Sans serif fonts do not have these. Both type styles can be used on a single map and are a common way of differentiating between different types of feature. For example, serif fonts are often used for natural features such as lakes, rivers and mountain ranges as the uneven form of the type mimics the uneven nature of natural features whilst sans serif fonts, which are more uniform, are used for man-made features such as place names. This is the case on the OS 25k and 50k series mapping.
Type characteristics
The characteristics of type can also be varied between upright vs italics, regular vs semi-bold vs bold and lowercase vs CAPITALS.
Varying the type characteristics (keeping the font type the same) can allow differentiation between feature classes such as a man-made vs natural feature or a place name vs a station name. Varying the type characteristics is more commonly used to indicate the relative importance or size of features, creating a visual hierarchy.
Try not to use too much bold text on a map as it can start to overshadow other map elements and make the map appear quite ‘heavy’, or too much italic text as it can become difficult to read.
Type size
The size of text is a very popular way to show the relative importance of features such as county, region, country. Visually, without changing other characteristics of type, users can visually perceive a hierarchy in the names. Maps typically use type sizes between 6pt and 12pt and most people can read 6pt without a problem so there is no need to use lots of large text which takes up lots of space and can be visually overpowering.
Type colour
Varying the colour of your text is a great way to differentiate feature types e.g. water features, tourist attractions, settlements, national parks and natural features. Colour can also be used to ensure that the text is clearly linked to the feature it represents due to colour associations. For example, blue is associated with water and therefore the label is likely to be linked naturally by the user to the water feature it sits alongside.
Changing the lightness (value) of the text can also be used to create a hierarchy, much like changing the type size or characteristics. Changing the lightness of type can also be used to make the text recede into the background.
Character spacing
The spacing of characters can be cleverly varied to show the extent of a feature where perhaps increasing the type size is not an option. Often it is used for features such as mountain ranges, water extents or countries. Condensed text is occasionally used where space is tight, but care should be taken that the text is still legible. More examples are included in the text placement section below.
Text placement
The placement of text can be one of the trickiest parts of making a map, or any data visualisation for that matter, particularly as automatic labelling engines in many GIS don’t do a great job. It is often the case that labels need to be placed manually, either within the GIS, or in a separate graphic design programme.
There are a few general best practice rules around text placement on maps:
Legibility is key – there is no point in adding text if it can’t be read. In order to maximise legibility, it is advisable to try and avoid placing text over map detail as it can make the text hard to read. If covering detail is unavoidable, a small text halo or mask can be included to help with legibility.
Labels must be placed so that there is a clear, unambiguous link between the label and feature it represents. To achieve this, it is important to place the text such that there is not another feature between the text and the feature it relates to. Further best practice for label placement for different feature types is discussed in more detail below.
Text should generally be oriented horizontally and should be readable from the bottom of the map (not upside down). Exceptions obviously exist where text is curved or diagonal along linear or aerial features or curved to follow the lines of the graticule. These exceptions are discussed further below.
In addition to the general best practice, there is specific best practice when it comes to labelling point, line and area features.
Point, line and area features
When labelling point features, the text should ideally be positioned just above and to the right of the feature it is representing. If positioning the label in this location results in the text sitting over detail, or results in conflict with another label, a sequence of positions should be considered. If the top right is not appropriate then the bottom right, top left, bottom left, top centre and then bottom centre can be assessed in sequence. The least preferrable location for labels is directly to the right or left.
The position of labels for point features should also be considered so that they enforce location, particularly in relation to linear features. For example, the label for a town located to the west of a river should be placed to west of the river to enforce this spatial relationship. The same goes for any boundary line, not just a river. When naming point symbols along the coast, towns which are actually on the coast should generally have their names in the water for legibility reasons. Inland towns should have their labels entirely on land. Placing names so that they straddle land and water should be avoided for legibility and aesthetical reasons.
Linear features include physical features such as rivers, roads and railways but also include theoretical lines such as borders and the equator. Text for linear features should generally be placed alongside and parallel to the feature but not touching it. Text for roads and rivers, if there is space, can be placed within the feature but should not cross junctions with other rivers or roads to avoid confusing the user. When labelling isoline features such as contours, the line should be broken to accommodate a label.
Ideally, a relatively horizontal or gently curving section of the line should be chosen and the name placed on a gentle curve which mimics the curvature of the feature. Complex curves should be avoided as the text becomes difficult to read. If a feature is vertical (or near vertical) the label should be placed so that if the text were to fall flat, it would not be upside-down.
Labels along particularly long linear features may need to be repeated to help user understanding. The repeated labels should be spread along the feature at suitable intervals and are often placed above or below large tributaries or road junctions to help the user follow a feature along its length with ease. This re-labelling approach along linear features is preferred to the exaggeration of letter spacing to show the extent.
Area features include features such as woodlands, mountain ranges, lakes, oceans and counties. If the feature is large enough, the label should be placed within it and the spacing between the letters increased so that the text is spread out across the area to show its lateral extent. The text can be rotated and curved slightly so that it follows the long axis of the feature or can be placed horizontally – both approaches are fine but it is best practice to keep the labelling approach consistent across your map. Care must be taken that the word does not get so extended that it becomes impossible to read as a single word. One exception to the letter spacing is where linear features are aerial in nature, such as a river. In these situations, the text should be placed within the river but should use normal letter spacing so that they are legible. Small areas may need to be labelled as point type features.
If you’re looking for more information in the placement of names, Swiss cartographer Eduard Imhof’s 1975 paper titled ‘Positioning Names on Maps’ (originally published in German) is a good place to start.
Making text legible
As we’ve already mentioned, legibility is key when including text on a map or data visualisation. When designing your text, consider the colour of your label vs the colour of the background. If the contrast between the two is low, the text will become hard to read. Increasing the contrast between the background and the text can help this. More information on the use of colour can be found here. The use of masks and halos around text can be a great way of making text legible, particularly where there is detail underneath the text. However, care must be taken to ensure that the halo or mask isn’t so large that it covers crucial detail beneath it. Finally, if space is tight and there is a risk of covering crucial detail or another label, leader lines can be used to aid legibility.
Read more about ways to make your data visualisation accessible here.
