cotton-polyester fabric
 

I just burned a snippet of one of the prettiest/nicest fabrics in my stash.


It has turned out to be a cotton-polyester blend!

When/Why did we become so "cotton only" for quilting/piecing fabric?

It's fine to use cotton-poly fabrics for quilting. There are just a few things you need to take into consideration.

Poly-cotton does not fade the same way cotton fades; it retains its original color. This matters if you are making a quilt intended to last a couple of generations, as the fabrics will not fade together. For example, look at the soft colors of a 30s quilt that has been used. Poly-cottons would stand out in a vintage quilt.

Poly-cotton frays more easily than cotton. As long as you are aware of this and can handle it, no problem.

Poly-cotton does not crease as well as cotton. This can become problematic with applique, where you want sharp creases while sewing.

Poly-cotton is more slippery than all-cotton, making it a little trickier to achieve accurate seams. This is more of a problem for beginning quilters than for people experienced in piecing.

Edit: To answer the original question, I think it became customary to specify 100% cottons for quilting simply because it avoids all of the above potential issues.

So, all or none, right?

I have mixed 100% cotton with cotton poly with no problem. Of course I don't expect my quilts to last forever, or even one life time. I make my quilts with love to be used an abused until they fall apart ! LOL Always wash 100% cotton first because if it shrinks it will shrink more than the blend.

And one other thing blends do, as bearisgray discovered, they melt at lower temperatures than cottons. They can also have a tendency to "pill" on the surface if they are not good quality. I admit I do use blends quite often and have occasionally melted a patch or two that I wound up having to replace. And I do mix them with 100% cottons. I try to stay away from 100% polyester fabrics for all of the reasons listed above, but sometimes the perfect fabric contains polyester, so I use it anyway.

I'm not surprised that the very pretty fabric is a poly/cotton blend. They are often gorgeous, probably because they are intended to be made into a dress, etc. I can usually tell if a fabric is a poly/cotton blend without resorting to burning. Often the frayed threads along an edge are noticeably thin threads, compared to what the frayed threads on all cotton fabric looks like. Also, since I prewash, dry and iron everything before it goes into my stash, I can tell it's a poly/cotton blend when ironing the fabric. I always iron on the hottest setting, which is too hot for polyester, so if the fabric is a poly/cotton blend, it will give off a pungent odor. I recently learned that colored polyester fabrics glow in a blacklight, so that's another way to distinguish them. Cotton will only glow under a blacklight if it is white. Anything white glows.