First Quadrant Done

My friend Sandy came up with a modification to my original idea -- she suggested positioning the background stripes as if radiating out of the central diamond. Here is the preliminary result.

I think it turned out well so far. Here are some close-ups.

It look me one false start, but here is how I made this quandrant.

I picked up 40 stitches along 'd' just along the edge, not with yarn, in the same proportions as for making the triangles.

I started at 'a' by knitting two stitches into the first stitch, knit back. Then knit twice into the first stitch, knit the next stitch together with the next picked-up stitch, knit back. After that, each right side row was: knit two into the first stitch, knit across, knit the last stitch together with the next picked up stitch.

Each stripe was 5 ridges wide. I had also picked up along the side of the large diamond and knew that was 55 stitches, which told me that I needed to have 15 stitches above the point of the smaller diamond (plus one edge stitch, created when I knit two stitches at the beginning instead of one). This told me when to turn the corner from A to B -- when decreasing one stitch each ridge after the turn would leave me with 15 + 1 stitches at the top of the diamond. This worked out to be in the middle of the sixth stripe, where after the third ridge, I started knitting two together on the first stitch (decreasing one instead of increasing).

For how I did C, let's move to the next diagram.

After reaching the tip of the small diamond, on the next stripe I picked up 40 along the 'f' side of the diamond, and then knit the last stitch together with the first stitch picked up from the side of the large diamond (side 'e').  Then I continued in the same fashion as before, decreasing one on the first stitch, knitting the last stitch together with one from large diamond along side 'e' until I had decreased them all away.

I can use this same method for the bottom left quadrant of the afghan, but I'm going to have to mirror the progression for the other two sides, starting from the tip of the large diamond instead of ending there. Otherwise, I will have the wrong side of the ridges on the front, which won't give me clean joins.

That won't be so much fun, because it means casting off along the side of the small diamond instead of picking up. In our next installment, I'll tell you how that goes.