It would be quite wrong to suggest that map-makers in the past were indifferent to the design of their products; indeed, some of the Elizabethan county maps were among the most aesthetically attractive. But in recent years increasing attention has been paid to principles of map design, balance and layout, particularly in terms of their visual effectiveness; to 'consumer demand', i.e. what the potential user of the map desires; and to the use of sophisticated psychological investigations to determine a particular design for a specific type of user.² A map can be regarded essentially as an integrated assemblage or synthesis of four categories of information: points, lines, areas and names, which are presented in terms of different shapes, characters, patterns, symbols, sizes, thicknesses, forms and hues. But these have to be considered not only as individuals but also in terms of their inter-relationships, so as to give the maximum overall clarity, legibility and visual impact. One important concept of design involves the presentation of information as a series of 'visual planes', what has been called the 'depth-cue approach', so as to create for the map-user a clear separation of the various distributions to be shown on the map. This is important, because a whole map is visible at once, a fact which can make successful map interpretation so difficult. An example of different visual planes is the tinting of the sea in blue as a background plane, against which the land and its detail are clearly distinguishable.