I bought a roll of light weight batting for Angela's rag quilt and it's very bunched up. I'm wondering if I can press it to make it flat again for cutting.

Put it in the dryer for awhile. That is much easier. :D

If it has polyester in it, be very careful and don't press it unless you use some sort of cloth over it.

I tumble mine in the dryer. It seems to work well,

I mist the batting (poly and cotton) with water. I don't make it wet, just mist with a spray bottle. Then I mist the inside of the dryer, load in the batting and put it on low heat and tumble for about 30 minutes. About half into the time I pull the batting out, fluff it around a bit, give it a good mist, and back in for the rest of the time.

While it is still warm, I lay it out as best I can and smooth it out and let it cool for about 10 minutes.