I don't know what a crumb quilt is. However, quilting over the seams is doable, but a little tedious. But, if you want to quilt Baptist fans, go ahead. You probably won't be happy with another design. Just remember your stitches will be larger in the seam area. Some people do a stab stitch in the seams. I haven't been able to do this so that it looks good on the back. I just take fewer stitches on the needle and accept the larger stitches. Also, I agree with Holice. I wouldn't recommend Warm and Natural either. I don't like it for hand quilting. Go with a thin poly, or if you really want a treat go with wool. It's like quilting through butter. It's my preference.