I'm wanting to knit a raglan sweater with a striped body and solid sleeves. I have some yummy Artyarns Supermerino, but I don't have enough for a sweater and I can't find all the colors I want in that brand. Can I mix it with, say, Cascade 220 Superwash (so both yarns will be washable)? Both are worsted weight; I'm hoping they will knit up to the same gauge. I don't have any Cascade 220 Superwash yet, but it comes in LOTS of colors.