New Stretch,
 

I have been searching for this answer.
My question is which is very unusual.
Can one Quilt/free motion quilting on clothing?
I want my outfits to have a flare and passazz to them?
Thankyou!

I don't see why not. I would recommend using some kind of stabilizer on the backside and double check your tension, as different materials may pull and gather and stretch differently. Run a test piece, and if it works, go for it!

Yes. The biggest issue you might run in to is loss of ease.

I would think it would be easier to quilt the fabric first and then construct the garment. if one wanted to embellish already sewn garments, I think an embroidery application would be better.

The Japanese art of Sashiko has been used for century's I believe to decorate clothing and also as a construction technique.

If you mean already made garments, I think it would “shrink” the garment. Also, if already made, you’d just be stitching on fabric as you wouldn’t be able to add a backing or batting. The way to do this would be to do the stitching on yardage and then make the garment.

I haven't quilted any clothing but have quilted fabric to make into items afterwards.

I’m making a vest type jacket and will be quilting the fabric, not sure if it will be straight line or other but the great thing about making your own clothing is you can do whatever you want on it. So I say do what you want to!

I have made a quilted jacket I had to quilt first then cut the fabric to be successful.

Sure. I used to do a lot of wearable art jackets and I did FMQ on most of them. Depending on the item and how much drape it needs, you can do more or less FMQ on it.

And, yes, you need to FMQ on the fabric first. I use either a twill backing and no other filler or a thin lining and flannel instead of batting so you don't get the poofy stand away from your body look. A jacket with batting can make you look 20 lbs heavier and I don't need that.