sorry to take so long to answer---
the background on my wool appliqued quilt is a fabulous double sided black flannel from Benartex---i love benartex flannels!
they are a joy to work on- i also love to do wool applique on flannel- but it is just as nice on regular cottons- homespuns- pieced backgrounds-
visit shops like:
Sue Spargo
Primative Gatherings
Backyard Gatherings
the Cotton Patch Quilt Shoppe
and the Quilted Crow
for inspiration- tips, advice, and supplies
there are many more- those are the ones that come to mind- my quilt was a Backyard Gatherings Project.