Piper George's Dutch MacKay kilt that I made for him is out of 11 ounce. Yes, it's light, but then again, here in California in the summer, that's not a bad thing.

I have several kilts out of 11 ounce wool/polyester blend, and I love them. They don't have the heft of a 13 ounce worsted kilt, and certainly not the mass of a 16 ounce, but if I wore nothing but that all the time around here, I'd ROAST.