> pww("twill_zigzag", "2/2", nrow = 15, ncol = 9)
/ - - - - - - - - - \ 
| X     X X     X X | 
| X X     X X     X | 
|   X X     X X     | 
|     X X     X X   | 
|   X X     X X     | 
| X X     X X     X | 
| X     X X     X X | 
|     X X     X X   | 
| X     X X     X X | 
| X X     X X     X | 
|   X X     X X     | 
|     X X     X X   | 
|   X X     X X     | 
| X X     X X     X | 
| X     X X     X X | 
\ - - - - - - - - - / 

