The Fall semester is over, the grades are in. My major sewing oriented project at the moment is revising my pattern program to work in inkscape as an extension. Thus far this has involved learning how use inkscape, python, svg, xml . It is nowhere near complete however I am making progress. So far, it only draws the yoke.
Some of the advantages of writing it as an inkscape extension are:
Inkscape is open-source
Inkscape is multi-platform
It is very easy to install extensions into inkscape. Just drop a few files into the inkscape extension folder and you are done. ( the major challenge on the Mac is to find the inkscape extension folder)
The screen shot below shows the inkscape window with the PPD-Shirt extension dialog.
Of course as I work on this program I realize ways to refine the program to make it more flexible. For example, giving the user the option of changing the shape of the yoke by adjusting a few parameters.
(Thanks to David Coffin for suggesting that a standard yoke should be included in the pattern.)
I expect to have a fully working version sometime in the Spring. I will have partial versions to play with before that.
Meanwhile, not wanting to spend all my time on the computer, I have been sewing a few more shirts (I still have much to learn about sewing shirts). Currently I am having fun with snaps instead of buttons. Snaps may not be as classy but they are way more fun to install.
White linen shirt with snaps and a shaped cuff:
I have also been experimenting with shaping the cuff. The goal was to make the cuff longer but have it cutaway around the thumb metacarpal so as not to impede the hand motion.
I also made the same shirt out of a pink chambray.
My next sewing project will probably be some trousers.
I did a very-very quick muslin of Joost De Cock’s “Textbook Trousers” at MakeMyPattern.com and they look very promising. Also, I am in desperate need of trousers.
This post is about the PPD-0102 pattern which is now available for download.
I am showing here a work in progress, ivory twill. I have not had time to complete it yet.
Eventually there will be step-by-step instructions and more photos.
The shirt pattern has its own page, PPD-0102 where you will find links to the pattern files.
My goal in producing these patterns is to help a sewist produce a shirt that fits well. The commercial patterns available for a sewist tend to come in the standard sizes 34-36-38-40-42-44-46. The skilled sewist is then expected to adjust the pattern as necessary to achieve a good fit. My initial plan is to produce the patterns in a finer gradation of sizes and hopefully make it easier to get a good fit (34-52 in 1/2 inch intervals). Eventually I should be able to offer custom sized patterns.
Admittedly this shirt pattern may not be of interest to the average sewist for a couple of reasons:
1) This pattern features a “shaped” yoke instead of the traditional “straight” yoke . I am considering making the next pattern with a standard yoke so that a standard basic dress shirt pattern would be available in a wide range of sizes.
2) This pattern looks a bit different than traditional sewing patterns although I do believe that the pattern is fairly clear (I still need to finish the instructions).
A remaining challenge is actually take measurements of a person and produce a pattern and a shirt for that person. I know it works for me, but that is a sample size of one. There are about 15 measurements that go into this pattern. I will describe these measurements in a future post.
In the meantime, I hope you find the patterns interesting and/or useful.
In this post I will try to examine the shape of the collar.
In my first pattern, PPD-0101, the collar is not quite right. I admit that over the last few months I put more effort into developing the software to produce a pattern based on body dimensions than I did on perfecting the pattern itself. Also, I admit that I do not quite understand the shape of the collar itself. So, in the pattern I produced a collar that seemed to work. As I now have more time to spend on the pattern, I want to understand the shape of the collar.
Several of the books I have on drafting shirts show something like the following from “Fundamentals of Men’s Fashion Design, A Guide to Casual Clothes” by Edmund B. Roberts and Gary Onishenko, 2nd edition, 1985, page 73:
They don’t say any more than just that ” A dress shirt has a crisp look and consists of a fall and a stand” They do not explain the shape or how they arrived at it.
When I look at one of my few sample RTW shirts I see this:
The collar seam does have a bit of curvature. The collar stand looks completely different. This shirt does looks similar to what I have seen In Kwik Sew Pattern 2777:
My impression is that the shape of the collar stand is not crucial to the fall. I believe the shape of the collar stand has more to do with fitting the neck and that this becomes more important as collar stand becomes larger and/or stiffer.
To study the fall, I am going to proceed on the assumption that a good fall can be achieve by shaping the collar only. I will test the different collar shapes on an un-shaped collar stand
I drafted the following three test shapes:
I then constructed the collars as normal and sewed them onto ribbon to test the shape of the fall:
And here are the results:
In Case A; The fall was so tight to the collar stand that I could barely get the tie on.
Case B is very good but the collar is still slightly pinched at the shoulder seam and does not flow smoothly over the over the knot (right side of image).
Case C seems to be the best fitting collar. The edge of the collar has a nice drape, the collar does not pinch at the shoulder seam and the collar passes smoothly over the knot.
What I have learned from this study is that the curvature of the collar at the collar seam is necessary to provide the volume between the collar fall and the collar stand. More curvature = more volume. Now it seems to me that the back of the neck would need less volume and less curvature and the front of the neck, especially in the area of the knot, would need more volume and more curvature. I will consider this as I play around with the collar design a bit more.
The next challenge is to understand the shape of the collar stand.
In this post I describe a bit about the pattern files and provide a sample file.
I identified my first pattern as PPD-0101. The PPD (Partlan Pattern Designs) is obvious. What about the 0101? I gave myself some room here: 01xx refers to a dress shirt design and xx01 referes to the first version of that pattern. Thus 0101 is the first version of my dress shirt pattern. I am already working on refinements to this pattern so the next pattern will be 0102. When I get around to a different style of shirt, say a polo, It will be numbered 0201. So much for the numbering scheme.
I have produced the pattern in sizes from 34 to 52 in half inch increments.
I am happy to give the patterns to anyone who is interested. There are too many to post on this website. Send me an email at email@example.com and I will email you the .zip file. Each .zip file is about 17MB.
I have uploaded a sample file. It is the .zip file of the pattern PPD-0101 based on the ASTM body measurements of 44 Regular: ASTMm44R.zip
This .zip file contains 10 .pdf files. Since I am planning for the home sewist who may be printing at home, I broke the pattern file into separate pieces.
The Collar (also contains the collar stand)
The Sleeve (also contains the sleeve placket)
The Cuff(1) a mitered corner barrel cuff
The Cuff(2) a rounded corner barrel cuff
The Cuff(3) a french cuff
A Test Page
The 10th file is the full plot (42in x 74 in) for those who have access to a 42in plotter.
If you are printing at home on standard 8.5x11in paper, you will need to test your printer to be sure it is not doing anything strange with the scaling. Hence the test page. Make sure “Actual Size” is selected in the print dialogue box.
On the Test Page ( and in all of the files ) is a 1in grid. Measure the grid after you print it and be sure that it is 1in in both directions. If it is not then you will need to play with the scale settings in the print dialog until it is. The grid lines will also help when you assemble the pages into the pattern piece.
The pattern contains 10 pattern pieces
Yoke (cut four)
Front (cut two)
Back (cut one, on the fold)
Collar (cut two fabric plus 1 of interfacing (optional))
Collar Stand (cut two)
Sleeve (cut two)
Sleeve Placket (cut two)
Mitered Barrel Cuff (cut four fabric + two interfacing)
Rounded Barrel Cuff (cut four fabric + two interfacing)
French Cuff (cut four fabric + two interfacing)
In up-coming posts I will present step-by-step instructions and discuss more details about the pattern.
In this post I introduce my Shirt Pattern Project.
I have always had problems with Ready-To-Wear (RTW) shirts. They are sold in collar size and sleeve length combinations. Thus it should be possible to purchase a RTW shirt that fits in the collar and the sleeve at the same time. This is sufficient if one always wears a coat. Collar size and sleeve length are all that matters. However, I don’t wear coats often. Thus, for me and probably many others, the shirt is an outer garment and hence it is desirable to have a shirt that fits well everywhere. The goal of my Shirt Pattern Project is to produce a pattern or patterns that allow the home sewist to produce a well fitting shirt. A tall order to be sure; it and may not be achievable. However, I should at least end up with a pattern that works for me and I will have learned something along the way.
Disclaimer: I have neither credentials nor experience in this field!
Here is an example of a typical inexpensive RTW shirt.
I don’t know if there is anything conceptually wrong with a curved yoke. However, I wanted to see if I could design a shirt that did not have this artifact.
Here is the result. Most of the curvature has been removed.
And the front view with the button-down collar. Mr Wolf sports a tie once in a while.
I don’t wear ties.
Here is the yoke pattern piece. This is a split yoke so that the grain could be parallel to the shoulder seam.
Here is the yoke on the form.
Here is the full pattern layout This pattern is based on my body measurements. A few of the features of this pattern are:
Cut-on front plackets
A front placket finale. This is the extra fabric at the bottom of the front. This makes a nice way to finish the front placket and transition to the hem.
A single piece sleeve placket which I find easier to sew.
I am using Adobe Illustrator to do the drawings. In addition to drawing the pattern in illustrator, I developed an algorithm to produce the pattern in different sizes based on body dimensions. I used the ASTM D6240/D6240M table of body measurements for adult males for the body dimensions and have produced the patterns in sizes from 34 to 52 in 1/2 in increments.
In the next post I will describe the pattern and sizes as well as upload a sample pattern.
Thread tension is a bit of a challenge: without it nothing works. Getting it right seems to take a bit of fussing. There are many good descriptions available of how to adjust the thread tension. The point of this post is less about setting the perfect tension than it is about understanding what is going on with thread tension. My goal was to measure the thread tension directly. Having access to a force sensor and some other incidental equipment that I usually use in the physics lab where I teach, it occurred to me that I could use the force sensor to measure the thread tension on the sewing machine.
I took my Kenmore into the lab and spent Friday afternoon playing around with this. The results are as follows:
As one would expect, the higher the tension setting number the higher the thread tension. The standard unit for measuring tension is Newtons (or mN): here I have converted the measurements into grams, another common way to measure tension.
The data here are the numbers I measured. I have no idea of what they should be. I have not been able to find any clear reference as to what should be expected for the top tension.
I also measured the bobbin tension. I found the tension to be about 35g. I used a digital scale purchased for under $10.
Having calibrated my top tension and the bobbin tension, I made various sample stitches to determine which setting gave the best results. The sample consisted of three layers of cotton muslin, Gutermann Mara 100 polyester thread, and a 65/9 needle. The best results were achieved with a tension setting of 5 which corresponds to a top tension of approximately 68g and a bobbin tension of 35g (I used a microscope to photograph the following pictures).
The microscope tends to reduce depth perception so I attempted to cut away the fabric to look at a cross section. You can just see the loop formed inside the fabric.
My best guess as to why there is a difference between the top tension (68g) and the bobbin tension (35g) is the resistance of the fabric. That is, some additional top tension is necessary to pull the lock-stitch into the fabric. However, I am no expert, these are only my observations.
Based on the above observations, I’m assuming that the correct thread tension depends on the following parameters:
Thread type and size
Fabric and weave
The desired properties of the stitch to be sewn
My next challenge is to explore these other combinations.
Thanks for reading.
A Sewist Creates Menswear Designs with Elements from Fashion History