Iron quilt batting?

My question is this--is it necessary to press the creases out of the quilt batting before making the quilt sandwich?  I know it's supposed to be smooth, so I would imagine it should have no creases.  Thanks in advance!

I've never ironed it but if it's been folded/rolled it's a good idea to shake it out and let it sit open or hang for a day or so before layering your quilt.  This usually takes care of any major creases.