I have that huge mat that goes on the cutting table that JoAnn's sells and I love it for squaring up quilt tops. I also have a slightly smaller one that goes on one side of my cutting table and one a little smaller than that , it's goes where my machine sits to cut pieces. Nothing is smaller than 36 inches and I love them. I want that rotating mat but haven't been able to afford it yet. I have been collecting these things for 20 years so it all comes in time. Get the biggest one you have space for and can afford.