Men's Upper Sloper
Some General theory[edit | edit source]
There's rather an art to pattern making. There shouldn't be, our goal in this page is to explore a bit and see if we can refine some of the age-old pattern techniques using more modern methods taking into account that we have software, such as Valentina to help us. As much "fun" as it is to draw patterns by hand, I often read pattern instructions that say: use a french curve until the curve looks right. I'm sure we can find something a bit more scientific. This is not only because the folksy way bothers my Engineering OCD, but also with the hope that we can avoid some of the iterations of making more Muslins (test garments) than necessary.
What's a System[edit | edit source]
Pattern makers usually refer to a "system" as a set of methods and techniques or algorithms that are used to create a sewing pattern. Each system is named after the author or school that has popularized it. I've been able to find roughly 50 or so different systems, although only 5 or so are specific to men's clothing.
Using some of the ideas I've gathered from other systems, I've tried to come up with my own, with the knowledge of how Valentina works and which would hopefully give us a more accurate pattern and one that integrates well with the way the software works.
What's a sloper?[edit | edit source]
Most systems start with creating a sloper (also known as a block). A sloper represents a bare bones pattern with minimal ease that's used to verify the measurements and basic fit of clothing to a particular person or model. In a way, you can also think of a sloper as a 2D version of a 3D dress form, starting with a well tested sloper, we reduce the number of iterations or having to start from scratch for every pattern.
The biggest problem with creating patterns is that it is mathematically impossible to create a 2D projection of a 3D object that captures all of the attributes of the original object. At some point you have to distort either the shape, or the perimeter, or the area or the relative position of the various parts (think, for instance, of a 2D representation of a globe, in the most popular projections, Greenland looks much smaller than it really is). On top of that, we're trying to create clothes here, fabric, depending on various aspects of it, is neither as flat as a piece of paper, nor conforms perfectly to 3D, so different fabrics require different shaping helpers (such as darts) to adjust the 2D pattern into the 3D body.
Measurements[edit | edit source]
From my very limited experience, the first challenge you'll encounter is getting proper measurements of your subject. Every system starts with a different set of required measurements. Valentina is awesome and lets us keep these measurements in a file that we can then use in our various patterns.
The system I'm designing uses a very different way of measuring that most other systems, I'll call this system "Radial".
In mapping the body from 3D to 2D to get the body of the sloper, other systems go around the body doing measurements. I believe we can get a better projection if we start by marking a point in the front and a point in the back of the body and making radial calculations (lines and angles) from there. Valentina is well suited to make lines with angles.
For this you will need a protractor, one that you can pin into your clothing.
I normally wear a tight fitting stretchy shirt to help me with this.
So the first thing you need is to find (or define) in your body the following 7 points (I've added a column so you can print this to gather your measurements). Note that F2, F3, F5 and F6 are the same points as B2, B3, B5 and B6.
Use the diagrams in Figure 1 to guide you as you identify, mark and measure the points.
|F0||Center Front Chest||-||-||B0||Center Back Chest||-||-|
|F1||Center Front Waist||B1||Center Back Waist|
|F2||Bottom Side Waist||B2||Bottom Side Waist|
|F3||Side Seam at Chest||B3||Side Seam at Chest|
|F4||Front Mid Arm||B4||Back Mid Arm|
|F5||Shoulder point||B5||Shoulder Point|
|F6||Shoulder Neck Point||B6||Shoulder Neck Point|
|F7||Center Front Neck||B7||Center Back Neck|
Once you have marked those points, print out 2 copies of the protractor in Figure 2, pin them to your body so that the center of the protractor is at the center of your front and back chest lines.
Now, for every one of those points, measure the distance from the chest center, and using the protractor, measure the angle to those points. Use Table 1 to record them.
On to Table 2... record radial measurements for the 8 well known angles in front and back. The angles are numbered from the portion of the circle they take (in 64th of a circle). We only take measurements every 1/16 Note that some of the measurements coincide with others you've already made.
In order to draw the best sloper possible, it's best to have a good drawing of the armhole. It's been hard to figure out how to do this, the best I've been able to do so far, is with a device I made out of an embroidery circle and some long screws (see figures 3 and 4). You put this device around the armhole, and tighten the screws until they are just touching the skin, in this way we can measure all the screws and get 16 points, which should be enough to draw a decent armhole. Note those points in Table 3.
|Id||Screw Length||Length from Center
(Circle radius - Screw Length)
|A16 (side seam)|
In addition, assuming you put your side seam at A16, Note here where in the circle the shoulder seam falls (Table 4)
(in 64ths of circle)
You need to get another 9 measurements, from the center chest and back, to 16 points in the armhole (half in front, half in back). These points were marked in the previous measurement section. It is important to have these measurements as it they will serve to draft an accurate armhole. Note them down in Table 5
To draft the sleeve, you'll need a few measurements:
|S1||Total Arm Length|
Finally, you'll need a few more measurements, these are used to validate that the rest is ok, or may be needed for further projects. Since you're in measurement mode, you might as well do them now.
|Chest Circumference||This is the traditional size of coat|
|Waist Circumference||The circumference at the point at which you use your pants|
|Abdomen Circumference||The widest circumference at your abdomen|
|Hip Circumference||Largest circumference at hip|
|Half Front Neck Circumference|
|Half Back Neck Circumference|
|Hip Depth at Front||Used to figure out shirt lengths|
|Hip Dept at Back||Used to figure out shirt lengths|
|Outseam (waist to floor)||Used to calculate crotch depth|
|Insteam (crotch to floor)||Used to calculate crotch depth|
|Crotch Depth||Used to figure out shirt lengths||Outseam - Inseam|
I've attached here a valentina measurement file with all of the measurements you'll need to fill in.
TO DO: attach here a Valentina measurement file
Drafting the sloper[edit | edit source]
This process will draft a sloper with no ease at all, not even for doing a test garment.
Armhole[edit | edit source]
Front Body[edit | edit source]
Back Body[edit | edit source]
Drafting the back body is basically the same as drafting the front body.
Sleeve[edit | edit source]
Sleeve theory[edit | edit source]
- On each side of the sleeve cap, the curve that goes from the cap line to the first notch should be identical to the corresponding portion of the front and back arm holes (i.e. 1/3 of the total distance) this section is the bottom of the armhole, and most people I’ve read don’t put any ease there.
- The rest of the curve needs to equal the distance of the total armhole, plus a certain amount of ease (I’ve seen systems that do 1 inch, or a given percentage, e.g. 8% of the total armhole, but see below for adjustments related to cap height)
- The total curve needs to fit into the sleeve cap height. The cap height in the sloper is measured as the mid bicep line (or in some cases, the total arm length minus the underarm length).
- Depending on the style, the cap height is adjusted: made shorter increases the bicep is widened and thus the shirt made more comfortable, the drawback is that you get deep folds forming at the underarm, so it looks less formal and less “tailored”.
Classic sleeves: Higher caps, 5-6”, more difficult to sew, more formal and attractive. Additional cap ease is needed to go over the ball of the arm (1.5-2”)
Casual sleeves: Less tailored. Offer more mobility. Cap height of 3-4” with about 1” of ease. Shoulder seam is lengthened 1-1.5” and shoulder slope is lengthened
T-shirt sleeves: very casual. Greater freedom of movement. Cap height of 0-2”, with 0-.5” ease. Shoulder seam is lengthened extensively. Sewing is easy, and because you have little ease, you can actually sew it before the underarm seam.
Drawing the main part of the sleeve[edit | edit source]
To draw the sleeve, you'll need the following measurements from your model
- Total arm length
- Underarm length
- Forearm length
- Biceps circumference
- Elbow circumference
- Wrist circumference
- Hand circumference
In addition, you'll also need some variables from the front and back sloper, mostly:
- All the parameters for the front armscye
- All the parameters for the back armscye
Drawing the Sleeve cap[edit | edit source]
Making a test garment to check fit and sizing[edit | edit source]
The sloper we've drawn so far contains no ease at all. In order to make a test garment you need a little bit of ease, here's where you should add it:
- Add 1/2 inch to the back shoulder line.... this gets eased into the front shoulder line.
- Add 2 inches at chest level (1/2 inch on each quarter of the body)
- Add 2 inches at waist level (1/2 inch on each quarter of the body)