This paper from SIGCHI ’95 detailed an attempt at blending the best features of paper sketching and computerized user interface design tools.
The main advantages of paper sketches is the ability to quickly draw ideas without getting bogged down in all the user interface details typical of full-blown user interface development tools like Visual Studio. Even many prototyping tools demand of the designer too many answers about color, icons, and line thicknesses for the early design iterations.
But paper has a disadvantage in that once something is erased, it has to be re-drawn again to get it back. While we learned that sticky notes can be great tools for temporary or movable parts of the interface, computers offer the ability to save snippets of drawings that are easily cut and pasted into many places. Paper also has the disadvantage of, at best, limited interactivity.
Computerized design tools excel at reusing components. Once a sketch is made on a computer, it can be reused many, many times. With the right software, designs can be quickly made interactive.
The tool detailed in this reading is SILK (Sketching Interfaces Like Krazy). It attempts to bridge the gap between hand-drawn images and interactive user interfaces. Users work with a computer drawing tablet. As they draw, SILK attempts to recognize interactive features. For example, scroll bars, buttons, and check boxes are common UI elements that the software can detect. Once a drawing is complete, SILK can attempt to create a GUI using the Motif widget set.