A few years back, someone posted on here to use aisle runners used for weddings. I bought a roll of it, but have not used it yet. To me, it looks and feels the same as the foundation used in String Quilt Revival by Virginia Baker & Barbara Sanders. I bought the book after seeing it featured on Sewing With Nancy. They used what was referred to as a Stabilizer, a lightweight transparent non-woven nylon mesh. I think that Ricky Tims sells a similar product by a different name.
You may want to check out the blog of Mary Johnson of MaryQuilts, a lot of free information and patterns, beautiful quilts.