100% acrylic yarn before and after steam blocking - absolutely makes a difference. When I started knitting and crocheting, I was told to never use acrylic because it can't be blocked. :
Blocking Acrylic Yarn: You Can and You Should | The Eli Monster
Why Blocking Acrylic is a Great Idea (Plus I Knit a Sweater in a Week, NBD)
Zero Water Needed to Block Acrylic Yarn in 2023 | Diy crochet, Crochet blocks, Crochet basics
Blocking Acrylic Yarn: You Can and You Should | The Eli Monster
A Modicum of Ingenuity: Tutorial: Blocking Acrylic Yarn