I'm as guilty of not wanting to swatch as the next knitter. Once I've selected a yarn and picked a pattern, I'm ready to cast on. I certainly don't want to knit a 4x4 square.
But I've learned, as we all do, that this will lead to trouble. Maybe not today, maybe not tomorrow, but one day, something that's taken a lot of time to knit won't fit.
Still, I thought it was going a little overboard when I first read Elizabeth Zimmerman's suggestion of knitting a hat as a swatch for a sweater to be knit in the round. I could delay casting on long enough to knit a 4x4 square, but a hat! That could take days!
But think how long it takes to knit a sweater. By knitting a hat first, you can measure your gauge from knitting in the round, try out stitch patterns or different color combinations, change needle sizes, and generally get a feel for the yarn and the fabric you can create.
So before casting on for a sweater in The Fibre Company's worsted weight yarn Khroma, I knit a hat. The Khroma is a soft blend of alpaca and merino, and has a great handspun feel. I like the yarn, I like the fabric, I like the color. I'm good to go.
And best of all, I've got a new hat when the temperature drops!