I am work and do not recall the name of product but I got it at my local quilt store and have see similar at JoAnn's. It is a white iron tape that you can use to join two pieces of batting. It appears to be a bit like a heavy mesh when you unroll it. It is about 1.5 inches wide and works really well. I have used it on baby quilts that have gotten heavy use and washing. I to make a point to be sure that my quilting crosses over the joined area but I did not do anything extraordinary. I keep using it with good results. It sure has helped use up larger scraps and you can not see any difference in the appearance of your quilt.