I think it must depend on what type of quilt you are making. You can put anything in an art quilt. Applique quilts frequently have thin fabric as a foundation so that you can see your pattern through them as you fuse onto the blocks. There are Victorian style quilts with velvets, satins,and even laces etc as the predominate fabrics. Some quilts use denim. I think that if you have hard and fast rules then you are probably making the same type quilts over and over again. Maybe you would like the challenge of a different type of quilt made with different types of fabrics. Certainly when you are making a wall hanging you can use textured fabric that you wouldn't use in a bed quilt, even carpet if it had the texture for what you were trying to achieve.Think of a landscape with some carpet added to a dirt road and some raw wool added to the snow on a mountain top along with sequins for snow glitter. Anything goes in a quilt.