Originally Posted by feline fanatic

In my mind sewing should be pleasurable not an exercise in frustration. The stabilizer keeps the knit of the T from curling up and stretching as sewing. I have made at least 10 T-shirt quilts and I used an iron on interfacing for all of them. People have paid me over $400 to make them T-shirt quilts. So I would say I am making a nice product if someone is willing to shell out that much. And I have had several references so I know my customers were very happy with their quilts. If I were to attempt to make a T-shirt quilt without interfacing I would starch it to the point of being like cardstock.
I'll continue to use interfacing. The lightweight .99 per yard stuff from Joannes does not add any weight, does not make the shirts stiff and saves me untold amounts of frustration when piecing AND quilting the finished product.

Edited to add, all my T-shirt quilts were made using 1/4" seam. When T-shirts are made they use the standard 5/8" seam and every t-shirt I have ever purchased had serged edges so I am figuring that is the difference when making a t-shirt as opposed to making a T into a quilt. Additionally new knit does not have the same tendency to curl up like a well loved T-shirt. Also I had a client T-shirt quilt come to me for LA quilting and did not have interfacing. It was a nightmare to quilt do to the streching and I will never take one in again that does not have iron on interfacing