On the inside back cover of Columbia Minerva 732, published (I believe) in 1960 is this full page advertisement.
Well, I didn't know that Columbia Minerva, in addition to their yarns and threads, also produced a washing detergent. Of course, it's a good fit .... knit the sweater with Columbia Minerva Yarn, and then care for the garment with Wool-Kare.
I found a footnote in a Google book excerpt indicating the product brand was purchased from another company, but other than than, I've found no other references to it's history, other than a few newspaper ads.
And then, in 1964, the ads stopped. I assume Wool-Kare was a re-branded product (made by some other company, who applied the Columbia Minerva label). Perhaps it didn't turn out to be a profit maker and they called it quits in the Cold Water Soap Market.
And that, I admit not much, is all I know. Perhaps you know more and would be willing to share?
Thanks for dropping by,