These I did for some friends. I sold my stuff to a local gift shop for 12 years and I used to make these all the time. Over 12 years I probably made well over 2000 of them. these are some of my favorite designs to use.
I don't like to do the binding so I don't use binding. I aim for 8 1/2"unfinished for my tops and then I just use a coordinating fabric on the back. I've never used the insulbrite and dont' intend to. This works just fine for me. I sold them for 12 yrs and noone complained.
I use a dense batting - it is a Traditional batting made by Fairfield company. I get it at Walmart. I use two layers. The batting is very dense and it is poly. I didn't want cotton to shrink so chose not to use it when I first started out making these.
So I make my top lay it on the backing fabric face down and trim the back to match the front. I add two layers of batting underneath and trim to match.
Then I sew the layers all together leaving an opening at the bottom
I turn the whole thing right side out and poke out the corners. Then I sew a seam about 1/4" from the edge all the way around overlapping where I started and stopped. This will close your opening as well as creating a faux binding.
I sue borders usually and when you sew that last seam around the edge it can make that border look like binding.
Then I stitch in the ditch to quilt the hotpad. I also like to spray my hotpads with Magic Sizing to stiffen them and I iron them on both sides to make them flat flat flat!! They look better that way.
You can see more of the hotpads I made over the years here
http://www.quiltingboard.com/picture...-t18069-2.html
http://www.quiltingboard.com/picture...-t39973-3.html
http://www.quiltingboard.com/picture...-t23351-3.html
http://www.quiltingboard.com/picture...-t39233-3.html