Felting: Episode One "The Experiment"

In the last post, I mentioned making a felted hat. So I experimented with some very old inherited "Red Heart" 100% wool yarn. (This yarn belonged to my MIL who had great stashes of yarn and fabric which were culled as she downsized into assisted living.) This yarn is so old that the label gives no hint as to how it will behave. I was tripped up a bit by the words "washable colors". I wasn't sure if that meant "superwash" or "colorfast" or what. I think the yarn is old enough that it preceeded the days of superwash wool, though. But I didn't want to spend the time knitting something intended for felting that wouldn't felt. BTW, the 2 skeins were packaged in a plastic bag--original second-hand store packaging which had not been opened--and marked $2. I imagine it was purchased on a 50% off sale day, though. Nice.
So I knit a swatch.
Then the experiment began.
Ingredients included a bowl, very hot water, a potato masher and rubber gloves.
Nice. The swatch felted beautifully.
I can't find my camera, but the experiment was successful enough to cast on for the hat....
To be continued.