Cliff is awesome. The care and effort he shows rivals most Etsy sellers. (I have a Klein mug and gifted several more.)
I have fun with every Klein bottle order. When someone buys a Klein bottle, I celebrate by walking through our backyard garden, looking for new blossoms. I usually take a few photos and send these to my customer-friend.
This micro business puts me in touch with fascinating people (I've met kids in elementary school, grad students, Nobel laureates, even a delightful nut who made a 4-meter tall wooden Klein bottle for Burning Man). The kind of people you find here on Hacker News.
PS - with reference to your HN identity -- from my ham radio days of long ago, I once experimentally determined that a 1/2 watt, 600 ohm Ohmite resistor would burn up when inserted in a 120V outlet. Hmmm: 24 watts into a half-watt resistor? Yep, filled the room with that acrid smell... Don't try this at home.I imagine him as someone who just sits around hacking all day, writing up long essays in between fulfilling orders.