Drafting and anthropometry

I neglected to mention something I did like about the Fitting Systemâ„¢ of the week from yesterday’s post which in turn reminds me to tell you the first thing that really bugs me about any and every pattern or sewing book I’ve ever seen -excluding the vintage tailoring books. If you happened to reach the third measuring screen on myShape.com (you can’t advance through the pages without registering and plotting your measurements) you’ll arrive at a page that requests all of your vertical measurements expressed in terms of height. By this I mean that the absolute length of point A to point B as a percentage of body height or length. This is one thing that myShape.com did get right. A sample of what I mean is shown below:

Unfortunately, when pattern making books teach you to measure a figure, they never ask for vertical measures like the ones above. Instead, they ask for direct tape-on-the-body measures which is inferior to the above method. Below is a scan showing how to measure a dress form in order to plot those measures into a draft.

You might think this is no big deal but it makes a difference. I guarantee that your center back length (or center front) is longer with the tape on than with the tape off. The reason is simple. A curvy line that travels the same distance as a straight line is longer. Therefore let us suppose your tape on measure of CB length is 16″ but your vertical length measure is only 15.5″. If you’re drafting your waist at 16″ depth, you’re going to run into problems. For one thing, your center back is not shaped like a straight line, so why draft a “sloper” based on the assumption that it is?

In a nutshell, if you’re going to draft a straight vertical line (as shown in the draft above) you should use the straight vertical length measurement to do it. Once you have -for example- the vertical length of the CB neck to CB waist drawn in, you’d use the tape-on measurement to draft the CB curve. To the best of my recollection, I have never seen a book in which I liked how they explained how to measure. None of the sewing or pattern books. No recent pattern books anyway. They have you measure the wrong things then they expect you to draft on it. The patterns will never be right -unless you’re inordinately slender and short. The further your figure from average, the worse your problems will be. Drafting any other way doesn’t make sense yet we teach thousands of students a year to do it as pattern books show. No wonder “slopers” are rife with error before you’ve ever cut them for a test fit. I’ve been drafting based on height for years. It’s more accurate.

Instead, I like how professional anthropometrists measure in terms of vertical height. The thing to do is to draft lengths (CB, CF, hip etc) according to vertical measures and then get the extra length you need by adding the shaping. Personally, I don’t understand how the need of these measures is omitted from pattern books, it’s ridiculous. Particularly when you consider that most of the books on the topic of interior design do include them. Open any book that discusses the design of furniture, work stations or cockpits and you’ll find these charts. So why aren’t these included in pattern making books? How can we continue to protest we’re working hard to fit the populace when we’re not even using the right standards? The average architect or interior designer has better standards and they don’t even make clothes.

To aid in the correction of this apparel industry oversight, I’ve scanned five pages from one of my favorite reference books, Anthropometric Methods: Designing to Fit the Human Body by John A.Roebuck, Jr. I hate to stomp on anyone’s copyright but this book is long out of print (there’s one copy of it on Amazon for $272.). Two of the pages constitute a glossary; the words anthropometrists use to define the points of human measure which are different than those we use in apparel. The remaining three pages are diagrams which you can use as guidelines. Get page 1, page 2, page 3, page 4 and page 5 as needed and print those out for further study and reference.
[This post has been amended]
Julia provided a tip regarding the purchase of this book from the Human Factors and Ergonomics Society. This book can be purchased here for $20. If you’re interested in anthropometry and ergonomics, you’ll find lots of material on the HFES website.

Speaking of anthropometry (meaning the measure of man) I found a couple of books that looked interesting on Amazon. One is The Measure of Man and Woman: Human Factors in Design. If you select to browse the excerpt, on the third page you’ll see the range of measures regarding infants from birth to 24 months which just made yours truly giddy with glee.

Another book that looks interesting is Anthropometric Standards for the Assessment of Growth and Nutritional Status . I haven’t seen this book but cruising the table of contents and the index just makes my heart go pitter-patter. Lots and lots of lovely lists, charts and graphs of body size comparatives. Oh my, I almost feel faint. Have I mentioned I collect data sets? Some women collect tea cups; I think my perseverations are more useful. At least they serve to amuse me, keeping me out of trouble.

And speaking of mensuration (the science of measuring), I found this book The Measure of All Things : The Seven-Year Odyssey and Hidden Error That Transformed the World which is (judging from the reviews) in the vein of Dava Sobel’s books (Longitude, Galileo’s Daughter) which I enjoy a great deal. I’ve put all three of these books on my wish list.

This concludes this week’s regularly scheduled revisionist rant.

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