Does anybody have a source for the plastic coated cardboard (prefer pre-scored) used in making yard and political signs. We just put in a Roland 540i versa camm and have some customers that want CHEAP yard signs. This would be my first attempt at doing these on this machine. Any suggestions would be helpful. I told the customer we could match our competitors price but failed in researching my vendors supplies first. You can reach me at johnr@aboutmontana.net Thank you for your help!