URW offered a number of digitisation services and options to clients. Their recommendation was always manual digitisation from artwork, but under pressure from customers they also developed an autotracing method to speed up the process. As Dr Karow and his colleagues at URW recall* most of the fonts that were made in this way later underwent a lot of manual cleanup, or were redigitised manually, but in the hurry to make fonts available in new formats some customers shipped autotraced outlines with various kinds of problems. I’ve had to work with such outlines a few times, and share Dr Karow’s view that in the long-term autotracing didn’t really speed things up, because if you wanted good quality you would have to spend a lot of time cleaning up the outlines eventually. As well as problems in the autotraced IK data itself, I believe the IK-to-bezier conversion had further problems with such data, producing some really nasty outlines in final font format. This was never a problem with the manually digitised IK data.

*As explained at, for instance, the recent DTL font conference in The Hague.

Thanks for the elucidations.