Yesterday, I talked about Cornucopia shawls, and why I dropped the term “vortex shawls” and using this one instead. Let’s go ahead and discuss the construction of Cornucopia shawls – how are they constructed, and how to determine their size?
I’ve been asked multiple times which shawl pattern the featured image shows – it’s Flower Cornucopia, available as single pattern as well as part of my upcoming book on Cornucopia Shawls.
Cornucopia Shawl Construction
Cornucopia shawls are triangles worked sideways shaped by asynchronous increases and decreases as shown below.
Size and Shape of Cornucopia Shawls
The good news: You can determine the size and shape of a cornucopia shawl before even knitting a single stitch. Yes, really. It just takes a little bit of math… or maybe shawl design app. (Working on it!)
A cornucopia is outlined by two curves: two half-circles with radii r1 and r2, respectively.
The major question is how to approximate the opening angle of our cornucopia shawl. This can be done by looking at the angle α in the picture below.
Angle and Increase Rate Work Together
The angle α is determined by our total increase rate.
We increase at one certain rate on the right edge and decrease at another specific rate on the left edge as shown in the first chart image above for a 6/3 example (decrease 3 sts every 6th row). This creates a total decrease rate of three (3) stitches every six (6) rows which is the same as one (1) stitch every second (2) row.
Our resulting opening angle is given by subtracting the decrease angle from the angle created by the increases.
Increases every row create an angle of approximately 60° as shown below.
One decrease every second row on the right edge can be viewed as increases every second row on the right side (it creates the same angle).
Our resulting angle would be approximately 60° – 45° = 15°.
Other examples would be 60° – 30° = 30° for one decrease every third row, or 60° – 15° = 45° for one decrease every 4th row in total.
I know this sounds complicated but it’s easier than you think. Get out your graph paper and a pen and give it a try: combine any increase and decrease rate but make sure you increase asynchronously – like 3 sts every 6th row, not one every second – otherwise your cornucopia might not form as intended but you’d just get a slightly biased triangle shawl!
To provide you with another example here’s a chart for a 6/2 cornucopia shawl: Every sixth row two stitches are decreased here. It creates an angle of approximately 60° – 30° = 30°.
PS. If you wonder why an increase rate of every row which looks like the perfect 45° angle in the chart above results in an angle of 60° – well, that’s because knit stitches are not square!