I was reminded of this one because I've been relying on the
Buster Cube a lot lately to provide indoor exercise for my dog, since it's been too hot to walk him. (He's a black Lab, so he absorbs the sun's rays like nobody's business, and therefore doesn't tend to do well when it gets really hot out.) And, naturally, the cube keeps getting caught under the furniture. ;)
This strip was drawn before my style settled down. I'd been experimenting with pens and brushes, and here I used an ink brush, which creates an interestingly varied line. I do like that, but the trouble is that it's less convenient than a pen--you have to keep dipping the brush in the ink, you have to be careful about ink blots, you have to wash it off afterwards--too much trouble. So later on, I switched to a technical pen, which creates a more simple line but is much, much easier to use.
Except that I would not recommend the fancy Rotring Rapidograph with the wire inside--that's what I used at first, and they clogged incessantly. I now use a Sakura Micron pen, which isn't quite as even, but has the advantage of never clogging. Still, I'm tempted from time to time to go back to the brush, and I still use it occasionally in my editorial cartoons.