Most length measurements start somewhere but usually end at the waistline. Which means that knowing exactly where your waistline is, is absolutely critical. Before you start, take a ribbon or string and tie it around your waist, at the narrowest point of you body. The string much be horizontal to the floor, front to back. Some people believe that their waist is lower in the front, and want to push the string down. But unless you are wearing an Edwardian corset, the waist never dips in the front.
If you are wearing a corset, then the placement of the string is very easy to get. Without a corset, it usually isn’t where you think it is. The modern style has the waistline at or just above the hip. But the reality is that your waist is usually about 2″ above your navel, or even with your lowest rib. If in doubt, start there.
Back Length
The length measurement most people are familiar with is the Back Length. This is measured from the base of your neck, down the spine, to the waist. While taking this measure, is it crucial that you stand straight, with your head level. If you duck your head forwards, you will lengthen your spine and get too long a measure. Start at the top of the large bone at the base of the neck, and measure straight down to the string at the waist.
Easy and simple. This measure is listed on the size charts, and helps you choose sizes to select a pattern length that matches your body length. However, it really is only half of the issue. There are two sections of your body that make up the total back length. The upper back, from armpit level to nape of neck, and the lower back from armpit level down to the waist. And not everyone follows the same proportion rules of upper to lower black.
Side Length
I don’t talk about the side length in the patterns, because I find most people don’t want to sew with math. And any needed adjustments can be made during your mockup. But for those who want to solve problems on the pattern before the mock up, this is an excellent measure to get a good fit at the beginning.
For this measure, you will need a straight edge of some kind, like a ruler. Place the ruler high up under the armpit, parallel with the floor from front to back. Drop your arm and stand comfortably straight, with shoulder down and back. Make sure the person is not lifting their shoulder!! Then measure from the top of the ruler, just at the front of the arm, straight down to the string at the waist.
The Hidden Math
So now that you have these measures, what do they mean and how do they relate to the patterns? I have discovered that a person’s body length really has nothing to do with a person’s overall size anymore. Unlike modern size charts, which get longer when they get larger. Truly Victorian chose to keep the side length the same for all the sizes. **And that side length is 9″. ** Which means that if your side length is anything other than 9″, you know you need to adjust the lower body length by the exact difference. For example, if you measure 9 1/2″ side length, then you know that you need to lengthen the entire bodice pattern, (Front, Side, Side Back , Back) by 1/2″, between the armpit and the waist. Or the opposite, if you measure 8 1/2″ side length, you will need to shorten the pattern by 1/2″. (More on how to manipulate the pattern in another post.)
OK, so far so good. Lets move on to the second part of the math. If you make any adjustments for the lower back length to your pattern, remember to add or subtract that to the overall back length of the pattern. For example: you added 1/2″ to the pattern length for your side measure. If the pattern originally measured 16″ back length, when you added the 1/2″, the total pattern back length now measures 16 1/2″.
Now the last bit of math. Compare the newly adjusted pattern back length to your measured back length. If there is any difference, then this difference must be added or removed from the upper section of the Back pattern piece. For example: the new adjusted pattern length is 16 1/2″. Your back length measurement is only 16″. This means that you need to shorten the upper back pattern by 1/2″. OR if you measure 17″ back length, you will need to add 1/2″ to the upper back pattern.
You may end up shortening both upper and lower sections, or lengthening both sections. Or you may have to shorten one section and the lengthen the other. It can get a little confusing, so go one step at a time.