OMG, how wonderful that you were gifted all that batting! I like to use a heavy weight flannel on some of my quilts for that heavy feeling. I have also used decorator fabric for the backing, that really adds a lot of weight.

That's how I do trapunto on a longarm!!!!!

my son wanted heavy quilts for my 2 gs. so he bought blankets that were kinda soft. worked good if i do say so.but i wouldnt want them that heavy for me.yes i machine quilt them on my sapphire 870 . took my time and used a little heavier thread.

I have tried double batting on a queen size quilt and it did turn out pretty heavy, but nice, so it just depends on how heavy you'd like it. You might want to try a baby quilt with it first and see how you like the thickness.

Do a small quilt sandwich first. Sometimes you only get skipped stitches because it is too thick. If you are looking for warmth, combine warm and natural with a poly. Two layers of warm and natural is a waste since the quilt really won't be any warmer - just heavier. Not enough air space between the layers to add extra warmth as you would get with 2 blankets.

In my early, not knowing anything about quilting, days. I hand quilted using two layers of poly high loft batting. My DS likes comforter type quilts. Now I use several quilts at a time. That way I can keep making quilts.

I made a quilt (not long ago) and used 1 layers W&N and 1 layer Hobbs Poly Down. I loved this one.

I too have used batting that I purchased from Walmart and doubled the inside sandwich. It was very difficult for me to do, will not do it again.
Everyone has their own preference as to the use of Warm and Natural, but it is made to be very light but is oh so warm and comfy! Especially for use in baby quilts!
Good Luck to whatever your decision will be.

I'm going to see if my LAQ wil do one with another layer of batting. I too would love to sleep under a heavier quilt.

Judy Woodworth, recently took a class by her, states that she oftens quilts with two layers. One being wool and the second layer 80/20. The wool gives it a trupunto look. Just be prepared when washing and drying you may have to take a trip to the laundry mat. I made an oversized king, 120 X 126", double sided flannel with one layer of warm and natural and it takes over 5 hours to dry it in the dryer. I wash it every month as the doggies sleep with us.