Aha! I found the bag with the half-finished jacket. Also in the bag is the large piece fabric left after cutting out the jacket, which is more than enough for a pair of gloves.
I will make some practice gloves from similar fabrics before cutting into this pretty royal blue knit, which as I remember was not extremely expensive but is good quality so it wasn't cheap.
I need to make at least 1 pair of gloves to see if I'm even guessing right on which size to cut out. I'm guessing the thickness of the fabric will make a big difference to the way they fit.
My first 2 or 3 practice pairs will be using recycled Tshirt fabrics from souveniers that DH and I only wore once or twice. The shirts take up too much space because we never wear them, but the fabric is much too good to just throw in the trash or use for rags.
My only concern is they might be too stretchy for learning to make gloves -- but on the other hand, Tshirt fabric is sturdy and doesn't ravel, so it's easy to UNsew. I just checked the pattern instructions, and the recommended fabrics are stretch velvet, stretch satin, or stretch suede. Well, no, I'm not going to struggle with any of those for my first try!