Insist on using union made and printed banners. Here is a list of union made vinyl banner manufacturers in the United States.
Blue Donkey Signs
1239 State Avenue
Marysville, WA 98270
1-360-657-3223
Union Made Promotions.com
2225 Industrial Drive
Madison, WI 53713
1-608-238-9080
Dem Sign
2451 18th Street N.W.
Washington, DC 20009
1-866-477-2259
American Advertising
204 South Third Street
PO Box 565
Boonville, IN 47601
1-800-995-5415
Focus Ink Incorporated
335 Jefferson SE
Albuquerque, NM 87108
1-505-265-3497
Carroll Printing and Promotions
2907 Canal Street
Houston, TX 77003
1-888-234-7883
Colby Poster Printing Company
1332 West 12th Place
Los Angeles, CA 90015
1-213-747-5108
I have used Colby Poster Printing Company to print vinyl banners before. They do excellent work! You can call this company with your ideas and they will design a banner for you over the phone.