http://www.signfaces.com/

http://magicsigns.com/

http://www.wholesalesignsuperstore.com/

http://magicsigns.com/vacuum_forming.htm

http://safety.fhwa.dot.gov/media/sign_support.htm

http://www.outdoorsignsamerica.com/catalog.aspx?catid=customsignfaces

http://www.signbuilders.com/sign-faces.htm

http://www.adtechintl.com/orlando/sfc.htm

http://signweb.com/index.php/channel/10/id/337

http://www.hansonsign.com/plastic_info.shtml