Watson, do you think you may need to wash it to compress the fibers?
I use a wool pressing mat at work (LQS) and love it, I definitely noticed crisper seams.
So frugal me found some wool fabric in my stash and made my own. I also had a piece of finely woven wool gabardine and made a case cover for the small pad near my machine to keep the pad clean. For my large antique wooden board I had piece of wool over 50 years old; washed and dried it and used that.