Chart Problems, and Trying Again

I'm just about to start knitting the top of Bella Paquita for the 3rd time. This one had better fit, or I'll be ripping the yarn into confetti!

There seems to be a problem with the medium charts. Marnie is aware that there's an issue, but has not had a chance to look into it yet. I thought I should post about it in case anyone else tries to knit the medium size in the meantime.

I would normally have knit the "small" size, but my yarn gauge is off since I'm using Rowan Calmer, which is a thinner yarn. Doing some number crunching told me that knitting the pattern in the large size should work. Unfortunately, either I messed up the math, my gauge changed, or it's just because the Calmer is so stretchy, the top ended up being a little looser than I wanted it to fit.

Looking at the difference between the medium and large bust sizes, I figured the medium would probably be fine. So off I went and knitted the top for the second time. This time it was way too small. I couldn't figure out how I could have such a huge difference, when there was only 1.75" difference between the pattern bust size for the medium and large.

Looking at all of the charts, I discovered that the chart for the medium top is smaller than the chart for the small top.

At first, I just figured that somehow the charts got switched, and that the "small" chart was really for the "medium" size, and vice-versa. But after crunching some numbers, I'm not so sure that's really the problem.

I don't know how Marnie calculated the circumference for the size dimensions, but I tried this:

Number of stitches across back at underarms x 2 (for front and back), divided by 4.5 stitches per inch = bust circumference.

Small chart: (78 st x 2) / 4.5 = 34.7"
Medium chart: (76 st x 2) / 4.5 = 33.8"
Large chart: (88 st x 2) / 4.5 = 39.1"

The pattern sizes for the bust show:

Small: 34.25
Medium: 37.5
Large: 39.25

The small and large come out very close to my calculations, but the medium is completely off. If the small and medium charts were just switched, I'd expect to see the "small" size come out closer to 37". So maybe the small is really the small, and the medium is just wrong. Or, maybe there's some other secret to calculating the bust size.

So anyway, I've spent the day working out my own chart, that's a little bigger than the 'small', and hopefully I'll come out OK.

As for the bottom and sleeve charts, it looks like the small top matches the small bottom, and the medium top matches the medium bottom (I compared the number of stitches at the join), but for the sleeves, the small sleeves are really smaller than the medium sleeves. I won't worry about the sleeves until I get there.

On the plus side, I really like how the Calmer is knitting up, so if I can get the size to work out, I'm sure it will be great.