Look around your office. I am sure you’ll find one of these media — I think they’re called cassette tapes? Oh yes, they’re back! What do you do with all those? If you were Von Glitschka you wouldn’t. Visit his blog on the subject and talk with him about it. A snippet from his site,

Linear art (also called continuous line art or contour art) has seen a resurgence in the last five years or so in our industry. I’ve personally done linear illustrations for clients like a grocery store chain, magazine editorials, coffee companies, medical industry, Kleenex box packaging, and a Banks animated TV Ads.