The largest king quilt I have ever quilted on the machine was 120" X 120" BUT I did it in three sections of 40" wide each. Even then
it hurt my neck and back. I have a Brother Innovis 2500 quilting/embroidery machine which works beautifully but that quilt
about killed me. Since then, I usually only do baby quilts (or the occasional lap) on my machine. Everything else goes to my long arm quilter. I prefer my quilts to be soft and light ( don't like excessive quilting that makes them heavy and dense.) Since she uses Asian pantograph designs, it's expensive but worth it for the look achieved.