Tom Arah looks at the history, problems, solutions and future of designing for the screen.

Previously I looked at the history of desktop publishing (DTP) with its focus on print-based design and output to paper. However the advent of the Apple Mac and of the Graphical User Interface (GUI) into the mainstream of personal computing also heralded the opening up of an entirely new publishing medium and one that is set to become even more important than paper – the computer screen itself.
What made the launch of the Mac in 1984 so significant for screen-based design was that it broke away from the dominant, text-only, character-based display of its day and instead treated the computer screen as a blank sheet of paper - right down to its use of black pixels on a white background. By treating the screen as an addressable bitmap the Mac and its later imitators, most notably Microsoft Windows, enabled graphics and, crucially, graphical typefaces to be presented in rich onscreen layouts.

Bitmapped GUIs enabled typographical font handling

At its launch both the Mac’s bitmapped display and dot matrix ImageWriter printer operated in perfect harmony at 72dpi so enabling the same bitmapped fonts to be shared across screen and paper. However the quality of print simply wasn’t acceptable and, critically, a rendering system based on bitmaps simply wasn’t scalable. In particular bitmap-based rendering requires stored versions of every typeface and style you intend to use at every possible point size which quickly becomes unworkable, especially at higher resolutions.
This apparent impasse was broken in 1985 by Adobe and involved moving away from pixel-based bitmaps to programmatic vectors. With the PostScript Page Description Language (PDL) and its associated Type 1 font format both the fixed page layout and the scalable fonts within it were described mathematically – each page was a program describing its end appearance, effectively a full page vector drawing. At a stroke this programmatic approach to page rendering enabled resolution, device and platform independence based on the use of fully scalable typeface outlines.