When I started knitting I found out there was a magic solution to ill fitting garments - it was called "short row shaping". When I first saw these magic words on my screen I knew I needed to find out more. Especially since my first knitted garment didn't really hang right. I wanted to make sure that the next item I knit was a perfect fit. However it has been a bit of a long trek to find out how to work out the magic formula that changes a standard pattern, into one that fits. I think I have finally worked it out and thought that I would try and explain a little about my methods here on this blog so that I wouldn't ever forget my working out and to help others by compiling all my research in one place. I hope it helps other people wade through all the blurb that it is available.
I will start by listing my resources:
Vogue Knitting: The Ultimate Knitting Book
Yarn Forward Magazine Issues 15 and 16
White Lies Designs Shapely Tank Pattern
Knitty.com article by Bonne Marie Burns
Picking the brains of Elizabeth Jarvis at my knitting group.
It was by utilising the above resources and working through the Shapely Tank Pattern that I felt able to start thinking for myself about how the short row shaping thing actually worked and why. The first time I did the calculations myself was a bit tricky but I came up with the Boccolo Jacket. This jacket wasn't a snug fit but it wasn't intended to be really. All the hems lined up properly and there were no bits that stretched or gaped. The second time I worked out the calculations for short row shaping I decided to make a spreadsheet so I didn't have to work it out from first principles again. The short row calculations are pretty straight forward and I will try and explain them here.
Short row shaping doesn't increase the width of the garment at the bust, what it does is increase the length of the garment at the front in the place where you need it most. The above diagram shows that if you have a larger than average bust, the front piece of the garment is longer than the flat back of the garment. One way of adding extra rows at the front, and making sure the sides seams still match up, is by adding short rows. This blog entry does not tell you how to do wrap and turns to create short rows, it only explains how to use it in relation to bust shaping. There are plenty of good tutorials on the web to explain how to do wrap and turns or short rows in knitting so if you don't understand these terms, go and search for them now - then come back to read the rest of this entry!
By adding extra rows at the front the fabric becomes three dimensional rather than flat. The short rows essentially add extra length in the front between the wrap and turns, which form a fold in the knitted fabric to make it follow the curve of your bust, the line of which is shown above.
When adding your short rows you should start with the wrap and turn nearest to the armhole edge, adding a mirror image wrap and turn at the opposite edge of the garment, and work your way nearer to the centre of the fabric, with each wrap and turn at alternate sides of the garment. This pattern of wrapping and turning is shown in the diagram below.
If you are working with a garment which has an opening at the front, each front piece should only have wraps at the armhole edge but each turn should be worked twice, once at the armhole edge and secondly by turning at the central edge of each front piece of the garment, as though it were a normal end of row.
In order to work out how many short rows you need for your bust size you need the following information, worked out in inches:
(A) Measurement from the top of your shoulder to your waist at the back of your body.
(B) Measurement from the top of your shoulder to your waist at the front of your body.
(C) Distance between the points of your bust.
(D) Number of stitches per inch in your garment
(E) Number of rows per inch in your garment.
(F) Number of stitches in the front piece of your garment.
With this information you can work out how many wrap and turns you need and where to put them.
The first thing you need to do is work out how much longer the front of your garment needs to be than the back of it.
(B) - (A) = (G) Where (G) is the Additional Fabric Required at the front of the garment
Next you need to work out how many rows you need in order to make that additional (G) measurement.
(G) x (E) = (H) Where (H) is the number of rows required to create the right length of fabric at the front of the garment.
Each wrap and turn creates a two new rows so calculate how many are required:
(H) /2 = (I) Where (I) is the number of wrap and turns needed at each armhole edge.
So now that you know how many wrap and turns are needed to create your extra rows, you need to know where to place them. The reason you need to know the distance between your bust points is because you don't want to place any wrap and turns in that area of the garment. That is the area that we are trying make bigger. All the increasing must be done on the outer edges of your garment. It is also a good idea to add on a extra inch on either side of this measurement so that the wrap and turns don't form a line that points to the tip of your bust (if you don't add this increased measurement you will end up looking like a 1950's Sweater Girl).
(C) + 2 = (J) Where (J) is the area at the centre of the garment without wrap and turns.
To work out the number of stitches you are not using for wrap and turns you calculate the following:
(J) x (D) = (K) Where (K) is the number of stitches in the centre that will not have any wrap and turns.
To calculate how far from the armhole edge your closest wrap and turn should be we need to calculate the following:
((F) - (K))/2 = (L) Where (L) is the number of the stitch from each armhole edge which should have the most central or last wrap and turn.
The first wrap and turn should be a couple of stitches in from the armhole edge to allow for seams to be sewn up.
Each wrap and turn should be spaced out as evenly as possible in the number of stitches allowed.
The short row shaping section should start level with the bottom of the bust if you are knitting from the bottom up, or start level with the top of the bust if you are knitting from the top down. This does not need to an exact measurement because we are dealing with a knitted garment that has some element of stretch. This stretch is the reason that only the larger busted amongst us have to add these extra rows, so our bellies are not on display.
These calculations may look quite complicated but if you take them apart step by step you will get there in the end. I have created a PDF that you can print off, with a worked example and a blank form for you to use for your own calculations, using the above formulas.
I really hope that this blog entry has helped some of you. If you need any further clarification I recommend going to the sources listed above, which is where I got my information from, or you can always leave a comment and I will try and answer any questions you may have. Good luck in getting your patterns to fit you in the way you want them to!