I always purchase P&B White on White(WOW). It is beautiful, sews wonderfully nice quality (not hard or ruff), is consistently available and a reasonable price. I find the most of the JoAnns WOW not what I want and unreliable as to quantity and being able to purchase additional yardage (not that I would ever run out of a WOW background fabric - lol )
My go to choice is Virginia Quilters - they have "enhanced" their pictures of the WOW so that you can see what they have
http://www.virginiaquilter.com/cgi-l...047+1314338291
There are other stores that sell these fabrics but IMHO this site is the best as it is easy to see the fabrics.
My favorites are "Ornate Scrollwork", "Twirling Ribbons" and "Scrollwork Flourish". There are many others that I have purchased as well. They will tell you if they are out of stock on some of them - but the store is excellent to deal with.