jon, to complete the process (in rhino) you can
1.pipe the line ...I used .1mm as my pipe (you'll have to play with your own numbers for the results you want)
2.then I made a box and copied the lines ( for demonstration purposes)
3.then booleon diff. for end results
(left to right the line, piped line, copied and booleon dif. line)
you can use any kind of line or curve to make your guilloche pattern does this help you?
here you go!
Moderator: ToddMichael