When I asked my mother to teach me pattern drafting as a teenager, I did so with fear and trembling. Mom made it look easy when she just invented patterns out of her head or created them from my sketches, but I knew there had to be a lot of precise measuring, and perhaps even some fairly complicated geometry, behind the process. Math was not at all my favorite subject, so I prepared myself for the worst.
Mom laughed. She told me that there would naturally be careful measuring involved but that human bodies are not mathematically precise and never will be. She showed me the basic flat pattern making techniques to create a bodice sloper (sometimes called "block" pattern making) and then proceeded to demonstrate why that method couldn't account for the quirks and curves of the not-so-average human form.
Being the type-A perfectionist that I was, I already wanted to throw up my hands in despair. If taking precise measurements and laying them out carefully on a grid didn't yield a great-fitting sloper right off the bat, then how on earth could I create accurate patterns? That's when the real fun began. I learned to let go and enjoy the "sculpting" process of pattern drafting -- a process that is 10% measuring, 10% careful cutting, and 80% eyeballing, tweaking, and, well, playing with fabric and shapes!
The benefits of this method are many: You do not need a computer to do the work; you can approach each pattern as a work of art rather than a mathematical finality; you can incorporate period techniques without confusing a computer design program; etc.* You also do not need a lot of expensive tools -- a couple of simple curves and several basic sewing supplies (see below) will get you going.
This is the method I am going to outline for you in this series of articles. It has worked for me for 25 years, and, though I've learned more and added different historical techniques over the years, I haven't changed the foundational method. It works because it takes into account the non-standard human form and allows you to create garments that fit beautifully without horrific headaches in the process.
The Tools for the Job
1. A one-inch grid collapsible cardboard cutting board. These are available inexpensively at most fabric/craft shops. [Note: If you are in Europe, you may be working in centimeters instead, but all of Janet Arnold's Patterns of Fashion books use a one-inch grid, and that seems to be standard, so I'm just going to assume its use throughout all of these lessons.]
2. Measuring tape
3. Straight edge (ruler or yardstick)
4. Hipline curve (available at most fabric stores and online)
5. Armscye curve (French curves work great for this purpose as well.)
8. Tracing paper (architectural vellum is study and easier to use than tissue)
9. Lightweight interfacing
A dressmaker's mannequin is helpful if you plan to draft a lot of patterns, but it's not a requirement. I'll be demonstrating all the steps on my mannequin, as I cannot demonstrate on myself, but if you have a friend who can help you with measurements and fit-checking, you will not need a mannequin.
I use my mannequin with the wonderful Fit System from Fabulous Fit . This involves a knit pullover and a variety of foam pads to help round out your mannequin more realistically. Most dressmaker's dummies look a bit like a Barbie(™) doll--perfectly flat abs and a hard bustline. ;-) Here's where we start to make adjustments for reality.
This is the fitting system from Fabulous Fit (right). I'm going to show you how to use it on a standard mannequin.
This is the mannequin wearing the knit pullover with no padding(below, left). I really don't know anyone who looks like this. If you do, congrats! Now the rest of us will get on with padding the bust, hipline, and stomach areas. ;-)
Here I have placed a stomach pad and two hip pads. The pullover is rolled up out of the way (below, right).
Now I've rolled the pullover smoothly down to hold the padding in place. You can see that I've placed bust pads to give this "lady" a B-cup instead of an A. (We'll talk about cup sizes in more detail in lesson two.) Here's the side view(below, right). As you can see, the tummy now has a natural roundness to it.
Now, you don't have to own the Fabulous Fit system to pad a mannequin. You can do it with a fitted tee-shirt (get one a couple of sizes smaller than the mannequin) and poly stuffing material or cotton wadding. It will take a bit more smoothing to make sure you get a nice contour, but it's definitely do-able. Personally, I prefer to pad a mannequin no matter what, because it makes the form pinnable and easier to use.
When I draft patterns I intend to sell, I plug in the standard measurements used by the "Big Four" pattern companies. These measurements are on the back of all their pattern envelopes, but you can also find them online. (Here is a chart that has the European size equivalents). If you stick to these standardized sizes for patterns, then customers will know when purchasing a pattern from you that a US size 14 from you is the same as a 14 from any of the big pattern companies.
Now, I still have to explain to customers that pattern measurements are a far cry from "off-the-rack" measurements! That is one thing that constantly confuses folks who are new to sewing. They think if they are a size 6 off-the-rack, they'll be a 6 in patterns. But vanity sizing is notorious (at least in the States!), and pattern sizes always run larger. The key is to tell people to go by their actual body measurements--not by size numbers.
Another thing we will cover in more detail later is "ease" in patterns. One of the things I find a huge frustration in one big pattern company's "historical" costume line is that, while the pattern designs are accurate for the period, they incorporate four to eight inches of "ease" in the fitting! This means that a form-fitting (corset-fitted) gown will have four inches of "extra" room when you are finished making the dress in your "size!" This is ridiculous and just shows that the folks in the factory who translate the pattern design onto paper are not really talking to the actual costume pattern designer. They just let the computer model dictate ease, resulting in a big discrepancy between body measurements and final garment measurements. Form-fitting historical patterns should obviously have very little "ease." But, as I said, we'll get into that later.
Let's assume for this lesson that I'm ready to draft a new pattern design for a wide range of sizes. I always start with a size 14, which is in the middle of the range from 6-26. With an accurate 14 (European 40), it is easy to grade down and up to finish the range of sizes for your commercial pattern.
If you don't plan to produce patterns for sale and just want to create them for yourself, then use your own measurements in all the steps below to create your sloper. Just note that I'm using the US 14 measurements for my example in this lesson and the ones to follow.
Now, after padding out my mannequin, I want to check to make sure it accurately matches the measurements for a size 14: 36" bust, 28" waist and 38" hips.
To achieve exact measurements with the padding in place, you'll have to tweak the dials on your mannequin and ignore the numbers to some extent.
In other words, don't start with a 36" bust on the dials and then add padding. Dial down a bit and pad from there, measuring to confirm the accuracy as you go.
If you are measuring your own body, I strongly recommend having an assistant help, as it is very difficult to get an accurate set of measurements while attempting to hold the tape level. It's also tempting to "suck in your gut," which is something a helper will catch and prevent. ;-)
One quick note about shoulder width across the back. Very few patterns actually publish a shoulder-to-shoulder measurement. I have no idea why, because bodice fit is most certainly affected by the width of the shoulders.
I was told by someone at a major pattern company that the "standard" shoulder-to-shoulder measurement used in the sewing industry is 16", but I have found that that tends to be too wide. Most women have narrower shoulders (more like 15.5"). And, of course, few have wider-than-average shoulders. All this means is that someone, somewhere will always have to make adjustments in the shoulder area. That's just life.
If you plan mainly to create garments for yourself, then use your own shoulder-to-shoulder measurement to create slopers. If you plan to sew for many people, then my suggestion is to measure all the ladies in your family and as many friends as are willing, then average that out to find a median shoulder measurement.
Again, "standard" measurements are only averages -- there is no such thing as a "standard" woman.
Okay, now you have a full list of bodice measurements (right).
Making the Bodice Sloper
A sloper is a basic body "block" that exactly fits to the measurements you've taken and becomes a foundational template for all your future designs. To begin work on your bodice sloper, you will need to have the tools from my list above ready and waiting. Grab your one-inch grid cutting board and lay your tracing paper on it. Reach for your marker, your ruler, and your curves.
Repeat these steps for the bodice back sloper, and you'll quickly find out why mere mathematics (no matter how carefully measured) cannot produce an accurate pattern piece! In the photo (below left), I've lined up the bodice back sloper over the bodice front sloper, matching the waistlines and center back/center front lines.
As you can see, the back shoulder is much higher than the front. To get an accurate rise for matching shoulder seams, you will need to trace the front shoulder rise onto the back (below right).
Cut away the excess, and your piece looks like this (left). Holding the modified back sloper up to my mannequin, I can see that the shoulder rise matches, and I have a small neckline curve in place (right).
Now it's time to cut out your slopers with lightweight interfacing or muslin and start seriously tweaking the fit for a real human body. First, remember to add a seam allowance to the side seams, shoulders, and neckline areas. (I'm using a 5/8" seam in my photos, but you can add whatever seam allowance you prefer; just make sure it's consistent across all pieces.) Here is the front sloper cut out with seam allowances in place (below right).
Now put your interfacing sloper onto your mannequin, pinning the seams and cutting down the neckline if needed to fit a real human neck. You'll end up with a totally form-fitting bodice without any ease.
You'll notice that the bustline is begging for darts, but you can ignore that for now. Darts, gathers, and other design elements will come in later when you use your basic sloper to create historical fashion patterns. Here's the front and back view.
One final "tweak" area has become apparent. Remember the ribbon we tied around the natural waist? You'll see that the sloper creeps above it about half an inch. Again, this is because flat pattern making would really be ideal for Twiggy, but it's going to fall down, er, flat when it comes to a nicely rounded torso with an actual bustline. Any cup size over "B" is going to cause "rise" in the bodice, pulling up the center front and affecting fit all the way around. For now, just jot that down in your notes and mark the needed extra length on the master slopers you will trace from these finished ones.
If you plan to offer patterns for sale, you'll go ahead and make a set of front and back slopers for each standard size you want to use, following the instructions above (you can even trace them onto cardboard to make a sturdy set). These slopers become your templates so that you will always have standard bodice shapes on hand and ready to trace. You won't have to mess with creating a sloper every single time you want to make a new pattern. You'll take the "standard" sloper and use it as a base to create the pattern you want to make. And that's what we'll be covering in the rest of our lessons!
Next time: Using Your Slopers to Draft an 1812 Bodice!
* Note: I get asked all the time why I don't use fancy CAD software to design my patterns. I've tried several, and I have never been happy with the results. For one thing, if you are designing historical costume patterns, these programs will be confused by the odd shapes of armscyes, dropped shoulder seams, etc. and will try to "fix" them for you. Forcing the program to accept your unusual shapes can become so infuriating that you'll be ready to take a sledgehammer to the software. But I even tried these programs for a fairly modern-looking 1940s blouse and found that, while the software didn't try to alter the pattern pieces, it did invariably add way too much "ease," resulting in a garment that fit like a tent. Doing the mental math to figure out how to trick the program to add less ease became headache-inducing, and I finally gave up. Every now and again, someone will convince me to try yet another "new and improved" CAD program. I'm always willing to make another test run, but I've yet to find a computer program that can match the human eye and brain for accuracy in fit, ease, and overall style. :-)