Buttonhole Scarf

I'm knitting my father a buttonhole scarf for Christmas. I went to The Knitters Studio, on 3rd Street in Los Angeles, and found a gorgeous Debbie Bliss alpaca silk aran. I'm using taupe and denim, and the plan is to knit 2 lengthwise stipes on each side of the scarf in the denim. Oh, I also bought Crystal Palace Circular Needles, size 8.

I found a lot of patterns for buttonhole scarves, but I wanted to knit this lengthwise, so I had to figure out how to make the buttonhole lengthwise. So I knitted a swatch! Crazy, no?



So I ended up binding off in the middle of one lengthwise row, and then casting on in the next row to create the buttonhole. I tried a couple of different knitted cast-on techniques, but I always ended up with either the yarn or the stitches on the wrong side of where I needed to continue knitting. (Sorry this isn't very clear, I still don't REALLY understand all the casting on methods and how and when to use each one.) So I ended up doing a double cast-on, which allows a seamless continuation from the row forming the second side of my buttonhole.

So now I have the swatch, I'm knitting garter stitch, because I want it to be warm, and because I want it to be the same on both sides. The plan is to knit thus:

20 Rows taupe
5 Rows denim
10 Rows taupe
5 Rows denim
20 rows taupe
2 buttonhole rows
20 rows taupe
5 rows denim
10 rows taupe
5 rows denim
20 rows taupe

Okay, Now I need to measure that and see if that will actually work. It occurs to me that my row numbers don't HAVE to be divisible by 5.

Maybe I should actually measure my gauge before I start this.