I think when we think about size grading, we're primarily thinking of sweaters even though size grading is going to play a part in everything from hats to socks to gloves - don't even get started on all the little people wears like soakers, rompers, and dresses - and figuring out where to start can be so daunting that it can cause designer brain freeze.
There are ways of working around this (so I'm told) and I have heard of designers publishing a pattern in a single size with the recommendation that if that size isn't your size, you can simply adjust the yarn weight and needles to make it larger or smaller as needed. I don't know about you, but I think that's bonkers and if I were a knitter looking for a pattern, one written this way wouldn't make it into my cart. However, there is another extreme in regard to pattern writing which is something that has been discussed in the design community at length: idiot-proof pattern writing. Again, I can't really be on board with this either - though not directly related to size grading, it's the polar opposite to the here's-the-idea-now-figure-it-out (and thanks for the money, btw) pattern. We've all heard the phrase: If you give a man a fish he eats for a day, teach a man to fish and he never goes hungry. I'm a firm believer that knitters should be educated, or at least have the ability to do a small amount of research in order to have a basic understanding of the techniques used in a given pattern. Though patterns are great resources and will surely teach you a lot, they aren't teaching devices. As a designer, you will find where your happy medium lies and how much you're willing to spell out in your own patterns. Once you break into designing with publishers, they will have their own guidelines and will be in control of how much information will be presented in a pattern. No matter what though, I promise you they will require size grading.
So, where do we start? How do you know all of the various measurements, and what measurements are actually needed to grade a pattern?
Obviously, it's going to be different for each type of garment, what the style is, and how the fit is supposed to be. Part of size grading is also determining ease (how much or how little is added or taken away from the actual body measurement) which is going to greatly effect fit. Certain styles lend themselves nicely to different types and amounts of ease which is something I think anyone who wears clothes, has a certain basic understanding of.
Let's begin with a basic sweater. The most basic sweater can be a cardigan or a pullover, it can have a circular yoke, raglan sleeves, or it can have drop shoulders. For this exercise, we're going to work through a traditional drop sleeve pullover from cast-on to bind-off, the progression of construction, and what measurements we're going to need. For the example, I'll show you the measurements needed to work a 32" actual bust measurement pullover and how to adjust ease and length. This pullover will be worked bottom up in rounds, the yoke will be worked flat, shoulders seamed, then the sleeves will be picked up and knit in rounds from the top down, decreasing to the wrist. The neckband will be picked up and knit in rounds.
First things first, once we have the basic idea down, we can put together a little flat schematic. For this I'm using some graph paper and assigning each square 2" - that means each square represents a 2" measurement. I used to use 10x10 grid paper and was able to assign each square 1", but this is what I have on hand so... making it work!
Most of the time, a publication is going to give you an example of their schematic and ask you to produce one similar with specific measurements included. All of the time, they are going to happily accept a little sketch just like this. I've labeled the measurements A-K in the order that they'll be worked - this is not necessary, it's just my way of working - but I give them letters so that on my document I can fill in A-K with all measurements in parenthesis and it's easy for the publisher to translate.
Now, I have worked so many sweater patterns that I can whip up this mock schematic without even glancing at my grade chart (I don't know if that's a good thing or not!), but you will obviously need measurements before getting pencil to paper.
You'll notice that the marked measurements cover the pullover pretty completely - again, different publishers will ask for more or less depending on their format and you will develop your own schematic style as you become more accustomed to working them into your patterns if you're self-publishing. You may also notice I have straight line measurements and oval measurements. I think this is self-explanatory, but for the sake of being thorough, the lines show length/width; the ovals show circumference. The armhole measurement "D" is length, the sleeve opening "I" is circumference because for this example pattern, the armhole is going to be created by working flat to a certain length and the sleeve will be worked in rounds from picked up stitches. Still with me? Okay... now to get more specific...
For the example, as I mentioned above, we are working an actual bust measurement of 32" but I'm adding 4" of positive ease for a loose fit, so the schematic shows 18 squares across (x2") for 36" circumference; measurement "A". The length, measurement "B" is 14" because the actual underarm to waist measurement for someone with a 32" bust should be roughly 7.75", but I want this to be just below hip length so I'm adding an additional 6.25" to the underarm to waist measurement. The upper arm circumference should be about 10" around and you'll see in the schematic that each armhole "D" is 6" - this is going to result in "I" being 12" but I've got little tabs at the underarm - these represent held stitches equaling roughly 2" (this includes the held stitches for the front and back) - making the actual circumference for "I" 14". This brings us back around to "C"... the underarm stitches are going to be held when we break for the front and back of the yoke at 1" on each side of the front and the back so, half of the circumference "A" is 18, subtract those 2" for the underarm stitches (1" each side for the front only/back only) and "C" is 16". Is this starting to come together for you?
When working the yoke, you can easily work the neck shaping by working the armhole depth minus the neck depth ("G" for the front and "H" for the back), then work the right and left shoulders separately for the front and the back. I normally work the bottom of the neck slightly more narrow and decrease along the edge at a fairly quick rate until the remaining stitches reflect the measurement for "E". For the simple drop shoulder, there is no shoulder shaping and the stitches can be grafted together, joined using a 3-needle bind-off, bound off and seamed - the choice is yours! The sleeves are, as I mentioned before, picked up and knit in rounds starting at the live stitches held for the underarms and working clockwise around the entire armhole. When it comes to shaping sleeves, there are many different ways, but for this example, we should look at the sleeve length "J" which is the full sleeve measurement minus the 2" cuff ("K"). We then need to figure out how many decreases it will take to go from measurement "I" to measurement "L" and how many rows will fit in between based on measurement "J". Basically, we need to reduce 14" (upper arm circumference) to 7.5" (wrist circumference) over the span of 14.5" (sleeve length minus cuff). I can go through the math with you based on pretend measurements, but there are tons of great plug & go systems out there for evenly distributed decreases. Obviously there are times when you don't want evenly distributed decreases (or increases if you're working sleeves from the cuff up), but for the sake of simplifying and staying in the starter's format, I'm sticking to even decrease rates.
HERE is a great sleeve calculator to get you started that calculates instructions for knitting in rows, rounds, and for machine knitters. HERE is another that gives increase and decrease calculations... and HERE is one more just for fun.
I know that this is a whole lot of information to try to digest all in one go! So, very simplified, when dealing with adding with ease, I usually add the bulk of ease to the bust circumference only. I add length to the sweater based on the underarm to waist measurements of each size depending on the style of sweater I'm going for. As a general rule, I add 6" for a hip-length sweater and 11" for a tunic length. These are the standards provided by the Craft Yarn Council - HERE is the full Standard Body Measurements page they provide. Sleeves can either be worked with no ease or very little ease and added based on the upper arm circumference measurement. I find that there is rarely a time or place for giant, over-sized sleeve circumference unless kimono, bat wing, or extreme dolman sleeves are part of the design. Also, related to sleeves, I often keep my sleeve length pretty close to the under arm to wrist measurement for full-length sleeves. I know a lot of folks love the long, cozy sleeves that you can tuck your hands into and that's great, too! It's just something you have to consider when developing your design. Remember that when working size grading, you will always start with the actual body measurement and make adjustments from there.
I've added a chart below for all of the pertinent measurements involved in a 32" bust for size grading, compiled over the years from dozens of sources. These are the measurements I work off of for my designs.
You can compare these measurements to the schematic and see that the neck opening, neck depth, sleeve length, etc are all pretty close. The wrist, however is 5.5" on the chart and closer to 7.5" on the schematic. I always add a couple inches to the wrist circumference if I'm going to add a ribbed cuff. With my hand-knits I'm particular about dragging sleeves for wear and tear purposes. Again, this is something that will depend on your preference, the aesthetic you're going for and the sleeve style you're creating.
I have a file available for download that includes all size grading for women using various formats such as the bust measurement used in the example ranging from sizes 31 to 56, sizes as XS to Plus, and juniors sized as 3 to 17. This file is available for purchase HERE. Use these foundation measurements as a tool and adjust your ease and length accordingly to the look and feel you want in your finished garments.
Now, what's the next step? Back to gauge and stitches. It always goes back to gauge and stitches, doesn't it?? The next installment will be short and sweet. I will briefly cover how to translate all of those measurements into stitch and row counts, making adjustments depending on stitch patterns, and simple ways to work stitch patterns in to an ever-changing landscape.
Below are pieces I designed using the basic construction as in today's example - simple construction, drop shoulders with little or no shaping, lovely results. Small differences is ease, necklines, and length paired with a wide variety of yarns and stitches create a group where no two look remotely similar. They sky really is the limit.
Top row from left to right: Owinja Pullover (Berroco Yarn Co), Patou Pullover (Knit Picks Collections), Nineveh Cardigan (Knit Picks Collections), Frosting Pullover (Knitscene). Bottom row from left to right: Greco Pullover (Pom Pom Quarterly), Worthington Gansey (Interweave Knits), Latham Gansey (Family-Friendly Knits), Meeting Point Pullover (Holla Knits).
I leave you here, the same as always...