a member of the kniftyknitterlooms group at yahoo asked me to come up with a pattern for a ski mask. having never actually worn one, i had to do a little online searching to make sure i knew what it truly looked like--the only image that came to mind before the search was the thing that bank robbers wear, and i didn't want to find out if that was the intended purpose. turns out, there are all kinds of ski masks--some with an opening just for the eyes, some with an opening for the eyes and mouth, some with separate openings for each eye (although so far i haven't found one with an opening for the nose--which seems like a more logical place to have an opening than the mouth but what do i know, i've never been snow skiing). anyway, my point is that since there are all kinds of ways to make them, i will describe the simplest way and then some variations. (i won't get around to making a sample for quite some time, so this description will have to do).
i would knit the mask being more or less like a long hat. start with 2 X 2 ribbing for several rows so that you don't have a rolled edge (unless that is what you want, in which case knock yourself out), then you can change to regular knitting if you like. knit in the round until the mask is long enough to reach from the mouth to however far down the neck you prefer.
to make a slit for the mouth (or for the eyes, for that matter), you simply bind off as many stitches as needed at the front of the mask. for example, if using the green loom, you could knit 16 pegs, bind off the next 4 pegs, then finish knitting the remaining 16 pegs. you could bind off fewer for a smaller person, or more for a larger person. then you would wrap the loom again as usual, including the pegs you bound off. you knit the pegs that have two loops on them, and then you are back to knitting as usual.
continue to knit until the next section is long enough to reach from the mouth up to the eyes, then make another slit--this one a bit wider--and finish by knitting until the top is long enough. bind off with the gathering method.
you could crochet around the slits to reinforce them, and that would give you an opportunity to create a bridge between the eyes if you so choose.
you could also go all out and embellish an actual face on the mask--you could make a pirate with an eye patch (oops, i bet depth perception is pretty important for snow skiing), you could make a braveheart warrior design, you could be one of the characters from "cats"--let your imagination go wild! there was an infamous set of ski mask patterns at the swapatorium that made the rounds online for a while, but i recommend them only for very small children--who do not really care yet what other people think of them--or for those who don't really like people anyway. :)
to the member of the kniftyknitterslooms list who needed this pattern--if you're planning on robbing a bank--go for bland. you'll be harder to identify.