No , actually you could cut it into other shapes ,but you will need to be either good with cutting or simply cut a a little bigger rectangular than your need then cut it again with something like this http://www.dealextreme.com/details.dx/sku.12590 (I got it from dealextreme and since then it come into many uses for me), as you can see it got many holes that you can use it to control the edges of your rectangular.