If you are going to use iron on interfacing, I find that the sheer weight Pellon works the best. If you need a bit more stand up power, I would still use the sheer weight, but put it on the back of both the outside and lining fabrics. I have never been happy with the other weights/or generic brands. All that being said, there are lots of other weights of Pellon that I do use, but for very specific situations.

thank you for your reply :)

which type of pellon would you recommend to achieve the soft padded look that bags have? i also need the bag to stand up and not be floppy. i will be using a regular quilters cotton fabric for the bag.

thanks again!

I think a pellon fleece would work.It will give it body without stiffness.There are different thicknessess of it,and it also comes in a fusible.It's like what is put in placemats,and some people use it in wall hangings.HTH
Kathi