I had good luck reducing the shrinkage by pushing (compressing) the trim as I installed it, avoiding any tendency to stretch it. I found that the semi flat trim sold by CW (and most others) had shrinking issues as others have attested to. One of my sons clued me into another trim product that he had ordered from Amazon, that was pricier but was stable and had retaining grooves on the edges. At $80 plus tax for 100' it was almost a deal breaker, but after seeing the quality and design features, I decided to try it. As the old saying goes...."If you didn't like doing it in the first place, you won't like doing again" OR "The bitterness of poor quality lingers long after the satisfaction of low prices". I would not hesitate to buy the better quality again! Here's the link to the product on Amazon
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
JMAC