Blank Garden Flags

Hi all,
Are there any recommendations where to buy Blank Garden Flags, to embroider on or print heat transfer vinyl? Size would be 12"x18". Wholesale would be great. Also, would you recommend embroidering on that nylon material or would a heat sensitive vinyl material work? I have vinyl that can be pressed on awnings and umbrellas. If you embroidered, how to you handle the back of the flag, with all the tie offs and such?

Thanks for any and all help.

Michelle in Minnesota