(This pattern is also available as a PDF document and as a French translation on aufildesenvies)
This airy, half-circle shawl is roughly constructed like Elizabeth Zimmerman's pi shawl. It's very, very simple and can be knit at any gauge and to any size. The two versions here - a plain one in gray mohair and a ruffled one in blue wool - can be worn draped over the shoulders like a small shawl or wrapped around the neck like a scarf.
Here's the intuition behind it (more specific instructions are below): You start with four stitches, which will be in the center of the half-circle. The shawl is then shaped and enlarged by doubling the stitches at increasing intervals. For the stitch pattern, I've used an elongated garter stitch; on the right side, you always do a row of yarnovers, and on the wrong side you usually knit the knit stitches and drop the yarnovers, except when you need an increase row, when you knit all the way across.
-Fingering weight yarn, at least 150 yards (For the grey version, I used about 150 yards of handspun mohair. For the blue version, I used about 210 yards of wool dyed by the Northeast Fiber Arts Center).
- Size 8 circular needle. Length doesn't matter too much.
With fingering-weight yarn on size 8 needles, I got 4.5 stitches and 6 rows to the inch. But this pattern will work with any gauge.
The grey version is 36" wide and about 14" deep. The blue version has a ruffle added around the edge, to make it 41" wide and about 16" deep. Note: I did not block these!
Cast on 4 stitches
Row 1 and all odd rows: K1, [yo, K1] to end
Rows 2, 4, 10, 20, 38, and 72: knit across (this doubles the stitch count)
All other even rows: knit the knit stitches and drop the yarnovers
The best way to remember where to put the increase rows (i.e. Rows 2,4,10, 20, 38, and 72) is to count the number of plain garter ridges between them. The first two increases have no plain ridges between them. The next two have 2 plain ridges, then 4, 8, and finally 16.
For the grey version, I bound off after that 16th plain ridge, which is to say after row 70. For the blue version, I did the final increase at row 72, then knit 12 more rows (still in the elongated garter stitch pattern) for the ruffle. The more rows you knit after that last increase, the less pronounced the ruffle will be.
Use a flexible bind-off, or at least bind off very loosely.
I didn't block either of these shawls, because I like the texture as is. But you could block if you wanted to make the elongated garter stitch look lacier.