Clients include Harvard Business Review, Wall Street Journal, Reader’s Digest, Woman’s World, The Magazine of Fantasy & Science Fiction, Oatmeal Studios, Designer Greetings, Amazon, United Media and North light Books.
Tools include a Rotring Artpen and paper of varying weights, an iMac of unvarying weight, Photoshop (mostly weightless), and my brain, steadily losing weight.
Another set of tools: hat, lap desk, soft place to sit.
(I wrote the above in 2011 or so. Since then, I’ve replaced the pen with an Apple pencil, and paper for an iPad. I lost the hat, but I still use the desk. It’s probably around 90, in lap desk years.)
The strip was called Spot the Frog, and still is. It expired after four and a half years, which, coincidentally, matches the average lifespan of a Bullfrog. There are two book collections: Spot the Frog, and It’s Hard to Comb a Grass Toupee. If you’ve been waiting to buy a copy for a good price, you’re in luck. You can turn back the clock at GoComics.com and pretend it’s 2004, where the strip reruns.
Mark Heath cartoons 
Hey Mark,
Don’t see a contact page.
Do you do free lance work?
I do freelance, but my attention to detail wanders and doesn’t always return; thus the missing email address. I just added an email form to the Mark Heath page. I also have a Google number: 401 757 0637.
Many thanks for noticing the wayward address.