Yep. I’ve learned the hard way to prewash my foldover elastic (FOE). On my first introduction to FOE I briefly wondered if it needed to be pre-shrunk, but that seemed like overkill. Besides, most elastics are aren’t made from fibers you’d expect to shrink, right?
Intense frustration ensued when my first few pairs of self-made undies came out of the dryer with tighter elastics. They were still wearable, but not as pretty or as comfortable. Lesson learned.
After that experience, I conducted an experiment to compare damp pressing and machine washing as preshrinking methods. I’ve included some pictures to illustrate the differences.
Machine washing is the winner! It shrank a whole inch compared to the original swatch! And it’s the prettiest swatch after stitching too.
Dampening the elastic and giving it a good steam with the iron (lowest setting that has steam) also worked to a lesser extent. It shrank the swatch about a half inch and would be a great method for items such as bras that will be hand washed.
With that figured out, excuse me while I go wash the rest of my FOE before my next sewing binge.