[Excentro](http://www.excourse.com/excentro/ http://www.excourse.com/excentro/) is fun specialized software for creating guilloche or "Spirograph" vector design

[Excentro](http://www.excourse.com/excentro/ http://www.excourse.com/excentro/) is fun specialized software for creating guilloche or "Spirograph" vector designs like you might see on bank notes and contracts and such. You can bring the results over to your vector program of choice to integrate into a composition.