Many, many, many years ago, I subscribed to OMNI magazine.
It had some excellent fiction and great Science Fiction art. One issue featured a
story about designer
and his Designatures. He had names and also phrases like
"Merry Christmas" that had rotational symmetry.
The article inspired me, and I've been
making them ever since. The "Mark" one is what I use to sign
my art. If I ever get a tattoo,
it'll probably be this
It seems that most of my Designature designs (usually people's names) feature curved strokes (as did the original "Mark" -- it's evolved over the years). Unfortunately, my Java class doesn't deal with curves yet, otherwise I'd put some more examples here.
I guess I could've done this with an animated GIF, but where's the fun in that? With my applet I can easily produce other Designature animations. All I need to do is sit down with a piece of graph paper to work out the strokes, then I pass them as parameters to the applet and it does the work! It's even driven by a script to control the spinning etc.
So how do you design a Designature? Well, write the word or phrase (like your name) on a big blank piece of paper, then turn the paper upside down. Now try to re-write the text so that it's legible rightside-up but also matches the upside-down text. It's difficult -- sometimes it's a matter of making each character rotate into another, sometimes you need to "borrow" bits of adjacent letters (as the 'M' borrows from the upside-down 'R').
Note that designatures are also called "ambigrams".