These are probably too complicated, but perhaps some other, simple design that could be programmed into the machine?
These, on the other hand, are just a simple straight stitch across the top. The 'save the date' is rubber stamped with chalk ink from Paper Source.
Previously posted example of invitation with fabric insert here.
Speaking of rubber stamps, seems like this tutorial on making a pennant rubber stamp roller could come in handy.
(via The Storque)