LCD DISPLAY LEGIBILITY INFLUENCED BY TYPEFACES AND COLOUR CONTRASTS

The evolution of high resolution displays, especially liquid crystal displays (LCD) that are among the most commonly used ones, has contributed to a larger circle of display readers. Despite high resolutions, problems in the legibility of typefaces still occur. Many typefaces may well be readable in print, but cause more difficulties when being read on displays. The aim of this study was to examine the influence of colour contrast on the legibility on LCDs to establish which type style is appropriate for a coloured text to be legible. Two different, specially designed typefaces for display use (one transitional, i.e. Georgia, and one sans-serif, i.e. Verdana) were tested in a satisfactory light-dark contrast of three different colour combinations involving five colours, i.e. dark grey (#1A1A1A) on white (#FFFFFF), dark blue (#142451) on light grey (#D9D9D9) and red (#C62026) on light grey. The reading speed and fixations were analysed with an eye-tracking device Tobii 120X. Different texts in both typefaces at 12 pt (16 px), in 130% leading and all colour combinations were displayed on a 24-inch LCD display. The forty tested individuals were between 19 and 22 years old. The results showed that the selection of a particular colour combination and contrast greatly affects the speed of reading and legibility. Less visible colour combinations of text and background were read more slowly than the more contrasting or visible ones at both typefaces. At both typefaces, it was seen that at a slower reading speed, more fixations were needed and vice-versa. It might also be concluded that the transitional typeface Georgia is more legible than the sans-serif typeface Verdana. Nevertheless, it appears that different colour combinations had different reading speeds at different typefaces (transitional vs sans-serif). An appropriate contrast and colour combination can facilitate legibility on displays.