Welcome to part two of this series! In this post I’ll be covering the basics of grading up–or enlarging a pattern. This is perhaps the most often requested, since a lot of vintage patterns in smaller sizes survive. But if you need to grade down, then never fear–that is the next installment!
One thing I want to say before I get started is that this is my own method for pattern grading and this is by no means comprehensive. If you want to learn more indepth methods to grading, there are a lot of textbooks available that I’m sure get into more nitty gritty details and techniques than I have time to cover. But for grading up a few sizes, this is a good option for the home sewist.
That brings me to another thing I want to point out: this is a method that is best suited to grading up a few sizes at a time. Any more than 3 sizes, and you risk distorting the pattern edges. If you need to go from say a vintage size 10 (30″ bust) to a vintage size 20 (40″ bust), I’d suggest grading first up to a size 14 (34″ bust) and then to a size 20. Trust me: the larger the gaps between the pieces, the greater the risk you accidentally loose the edge integrity and throw off placement for things like darts. (Don’t forget you’ll also need to lengthen the pieces during the grading process, which I’ve touched on at the end.)
Final point (and then we’ll get started, I promise!): As I said in my previous post, grading does not negate the need for a fitting muslin. Grading is simply enlarging (or reducing) the pattern. It does not magically make it fit your body perfectly (unless, of course, you are one of those lucky people who can fit a pattern straight out of the envelope–how I envy you! hehe!). So grade, make a muslin, and fit. ‘Nuff said.
Begin by tracing your pattern–I never cut my original pattern to grade (especially vintage patterns), as I want to keep the original intact. I went over what I use in the previous post for tracing my patterns. Essentially, I lay the piece on my cardboard cutting mat (I usually iron it gently and on the lowest, non-steam setting first), and the transparent paper over top. I trace all the edges, markings and grainlines. Be sure to label each piece too! Cut them out once they’re traced.
For the example pattern, I’m going to say that we’re grading from a 32″ bust/24″ waist/34″ hip to a 36″ bust–a 4″ difference. We’re going to be doing an even grade (I’ll go over some of the basics of uneven grading later on in the series), so the overall grade will be 4″ resulting in a 36″ bust/28″ waist/38″ hip. Here’s where you’ll need to do a little math!
Take that grading measurement–4″–and divide by 2. This measurement (in the example it’s 2″) is what we’ll grade over the entire 1/2 of the pattern. (Meaning that most patterns have a half bodice front, half bodice back, etc.–it’s essentially half a dress!) Since we have a front and back piece for the bodice, we’ll divide this 2″ by 1/2 again to reach 1″. This 1″ is the total grade for the front or back. (So when you have graded your pieces and make a complete bodice, it’ll have been graded 4″ overall.)
We’re almost done with the math! Take that 1″ and divide it by 3. I never divide evenly, since it gets a little cumbersome. Generally I’ll do a 3/8″-1/4″-3/8″ division for a 1″ grade. You’ll see where these measurements go below. Write this down somewhere, since you’ll use this on each front and back piece to reach that overall 4″ grade.
This is the pattern I’ll be using as an example for the instructional portion of this post. It’s fairly simple, and I feel showcases the basic principles of pattern grading the best. Scroll to the bottom for a few more schematics of other pattern types too!
One thing I almost always do on pattern tracings prior to diving them (otherwise referred to as “slash and spread”) is make a horizontal line across the pattern. Your pattern may already have this in the form of a lengthen/shorten line, but if not, it’s a good idea to draw one now as it helps match things up once you’ve cut the pattern apart.
This shows the basic dividing lines for most bodice patterns: from neckline to waist, shoulder to waist, and underarm to waist. Note on the back pattern piece rather than going straight from the armhole down, I angled the line. This is because a straight line would have ended above the waist, which we also want to grade up. Note I also tend to avoid cutting in the middle of a waistline dart. Of course, your pattern will probably vary–but once you know the basics of where to place your lines, you’re set. I have rarely deviated from this configuration in the years I’ve been grading by hand–usually it works for the majority of styles.
To go along with our example grade (4″ increase overall), these bodice pieces have been cut along those dividing lines and spread the appropriate amount we calculated above. I tend to spread less over the shoulder to waist slash. Why? Because adding too much to that area tends to give a pattern “linebacker shoulders”. If you have to do a Full Bust Adjustment, wait to do that until after you’ve graded the pattern–don’t try to “cheat” and add it at this point!
This is how I usually set up my cutting board while I slash and spread the pattern pieces: a piece of paper underneath, and the graded piece (slashed and spread) pinned overtop. I tend to just retrace the entire piece. But you can also tape additional paper underneath if that’s easier. It really just depends on the size of the grade!
The last thing you need to do after you grade the pattern, as you’re tracing (or after you’ve taped in other paper), is to true the edges of the pattern as they’ve probably gotten a bit jagged with all this grading! This just means to connect with a smooth line one point to another as above in red (on the front piece). Cut out your new pattern piece (if you’ve traced, making sure you’ve transferred all darts, grainlines, etc.) and you’re done!
For more grading examples, click the “more” link below.
Skirts: Very easy to do! Even gored skirts. Below is the dividing line for a three piece skirt (one piece front, two piece back). Add the same amount you added to the front and back bodice pieces (generally I divide the measurements up the same, which helps with keeping things like notches and darts approximately lined up during grading).
Gored skirts are just as easy. Here’s a basic layout for the dividing lines for a six gore skirt:
Sleeves: These differ a bit from bodices and skirts in that you don’t take the entirety of that 4″ grade measurement and divide it into the sleeves. Rather take the total measurement that you added to the front and back armhole (in the example 3/8″ on each for a total of 3/4″) and divide it by 3 (so 1/4″-1/4″-1/4″). Below is the basic placement for the dividing lines. Slash and spread as discussed previously.
Facings: If you have a fairly complicated facing, you can grade it. But honestly if it’s a neckline or combination neckline/armhole facing (as I showed below because it was the easiest to illustrate), I just retrace a new facing once the grading is complete.
To Lengthen a Pattern: Usually if I’m grading up a size or so, I don’t bother to lengthen the pattern piece. But if you’re grading more than two sizes, I do recommend adding length to the pieces. Otherwise you might end up with something the right width around, but way too short! Generally I’ll refer to the neck to waist measurements on the back of the pattern envelope and calculate the difference (for example let’s say the difference for our 32″ to 36″ grade is 1/2″). But if your pattern doesn’t have this information, measure yourself and compare it to the neck to waist length of the pattern piece. Divide this measurement by two (so 1/4″ and 1/4″ for the example). Here are the basic dividing lines for a bodice:
For other pattern types, I highly recommend taking a gander at this quick guide from Threads Magazine.
In the next installment I’ll go over grading down. For those looking for information on my tricky styles (like raglan sleeves) or pants, those will be in a later installment. I think if I kept tinkering with this post, it’d never get published! lol. If you have questions, please feel free to leave them below. I can’t promise I’ll know the answer, but I’ll try to do my best to assist!