Yes, but most times it was by accident especially when using tone on tone whites. Don't realize they're backwards until you've already sewn then in. By then I figure if it took me this long to notice it, I'm sure no one else will notice it either.

Yes. I used the wrong side of a wideback because the right side was too bright. It was for a pastel baby quilt.

Often. I’ve never thought about it- I use the side that works best for my project - there is no Wrong side.

In Hawaii the style for men's Aloha shirts was with the bright, loud fabric to be sewn with the back side out. That toned down the colors and made some beautiful shirts.

Why not use the back side, if it works better with your quilt?

I have done this and have been happy with the results. The first time I was putting blocks together and accidentally put the fabric on wrong, really liked it and used it throughout the quilt. The difficulty came, probably from muscle memory, where you just immediately put right sides together. I had to keep reminding myself that the wrong side was the right side.

Yes, I've done this several times & it always works. Sometimes I've even done it by accident (like Snooze said above) and it still turned out good. I've even bought fabric for the intent purpose of using the back side because I liked it better than the front. I paid for it all....front & back.

I did this on a toddler quilt once, used the back of a red grunge to match the red in a novelty print (Thomas the Train) on the front of the quilt. I caught myself a few times trying to put "right sides together", but managed okay on the front. I backed the quilt in the same fabric - TOTALLY planning to have the same red showing as the front of the quilt. I had it completely made, washed and shown to my grandson, and didn't realize I had the grunge side showing on the back until I went to take a picture for my records, lol! Luckily it still looked "okay". Like Reader1 said, it's very hard to remember that the wrong side is the right side! Otherwise, I think it's a great idea if the colors work better. :-)

I've done it both on purpose and not on purpose. Fabric has two sides and I use the one I want. In the Grassy Creek Bonnie Hunter mystery, I used a heavily metallic gray print with both sides. In the bed of the quilt I used the back because I didn't want the metallic, but in the border I wanted the metallic elements to show.

Many years ago I made a Storm at Sea, I later figured I had handled each block about 27 times just in the sewing process, much less the layout and quilting of the project. I didn't notice until it was hanging in a guild quilt show that one of the large center squares was "inside out". If anyone else ever noticed, they didn't mention it to me. That was when I really felt reassured that it was ok to use either side. It wears the same, and if it looks better -- do it!

Two Sidess
 

A great quilter once told me. Every fabric has two sides.

Sometimes the back of the fabric is just right and using it throughout your quilt will give it the piazz it needs. Don't be afraid to use the back throughout.