|This comes from Calligraphy Alphabets Made Easy. That's why it tells you to "turn the book around..."|
There are four levels of transformation by rotation, from no-brainers to real challenges.
- Some letters virtually don't change: o, z, s, x. You could cross t in the middle, omit the dot over i.
- Many of the letters are simply transformed into other letters when rotated; d to p; b to q; n to u.
- Some are somewhat the same: h and y; f and j; m and w.
- A few stubborn characters just won't change into anyone but themselves, and you have to hope that the context will make them readable; v, k, c. These are indicated as outlined letters above.
Ambigrams were pioneered as "inversions" by Scott Kim.