I'm curious about your seams-- did you use 1/4" seams on the linen fabrics? I used linen for backing a baby quilt last year and loved the weight and softness of the prewashed linen. I sew primarily with linen for clothing, so I know about its tendency to ravel and usually french seam or serge the raw edges for them. I've wondered if quilting across the seams is enough to prevent fraying.