#KnitPetiteProject: How is the standard for petite different than the standard misses/women?

Our last post outlining how we arrived at the standard we have today.
The #KnitPetiteProject plan.

All other #KnitPetiteProject posts.

In anticipation of the standardized chart comparing we’ll be doing at the end of the month, this post will look at some of the differences that exist in the ASTM size charts for Misses and Misses Petite.

ASTM: Comparing Misses’, Misses Petite, and Women’s Plus

astm1
Wikipedia article

The ASTM sizing standards are a good place to start when comparing sizing differences: while they are indeed voluntary for the apparel industry, they are influential, regularly updated, created through various expertise sub-committees, and relatively inexpensive for individuals to obtain (charts cost around $45). I know these charts are used by some designers within the knitwear industry; Ysolda’s newly updated chart cites ASTM data as one of several sources.

As the full charts are behind a paywall, I’m only sharing the above information from Wikipedia and a few comparison points below. This will give you a general idea of the area of difference within ASTM as an influential organization’s suggested standard.

To clarify: as I know I certainly get these numerically-referred to charts confused: the Misses’ Chart is ASTM D5585, the Misses’ Petite is ASTM D7878, and the Misses’ Plus is ASTM D6960. I must apologize, as I don’t currently have a copy of the Women’s 55 years and older chart ASTM D5586; I hope to get that one soon and be able to include it in comparison in the future.

chart

A few things to note about this chart:

ASTM develops these tables from a variety of data sources including: the U.S. Department of Commerce, the Caesar study, SizeUSA, current U.S. industry standards, and studies, scans and documentation from Alvanon Inc. They have also included variations in size for curvy and straight body shapes, as you see above.

These charts leave out an upper size range in the petites, cutting them off at a 46″ bust. They also increase the backwaist length through all three charts (even though they take as standard a particular total height). The backwaist length at its shortest in petite is 15″ 3/8; the same bust size in regular misses is 16″ 1/8 and the smallest plus size has a backwaist length of 16″ 1/2.

An important take away: check the garment schematics for your knitting patterns. Good patterns will have good schematics with many different measurements included. Something important to look for is that total body length / sleeve depth / bottom of sleeve to bottom hem.

It’s also important to note that these charts we’re looking at today are body measurement charts, and that knitting schematics are (supposed to be) measurements of the finished knit, NOT the body. Designers have taken into account ease of various kinds and amounts depending on the style and body part being covered. Confusing, I know! But if you peek forward in the #KnitPetiteProject Plan, you’ll see I’m hoping we can have a KAL later this year where we can all work together and help each other understand our own petite needs.

SizeUSA

The study we looked at in previous weeks compared the regular and petite sizing from SizeUSA:

The petite group showed significantly lower mean values than the regular group for all the vertical measurements. The petite group had a 3.7″ shorter stature, 2.16″ lower crotch height, and 1.26″ lower knee height on average than the regular size group…. The petite group also had significantly shorter lengths than the regular group by 0.14″ at shoulder length, 0.82″ at the back waist, and 1.52″ shorter for arm length. pg 55

Interestingly, this study also found significant differences in the SizeUSA data between the widths of regular and petite women. We might guess this is obvious if we think about the way we culturally use the word petite. But something that may NOT be obvious is the numbers show that petite women had a smaller drop value between waist and hip than the regular group (that is, the difference between waist to hip, or bust to waist).

As a reminder, this is the study we looked at that outlined different ways you can be petite, from top petite, bottom petite, average petite, and plus petite. It might make more sense now that I remind you the ASTM charts, according to this study, most closely matches the measurements for top petite.

You Should Read This

As the #KnitPetiteProject progresses, I keep reading! I’ve already come across (new to me) sources filled with info that anyone can access, and are topics that have already been addressed in previous weeks’ posts.

I figured, instead of going back and editing those old posts, I’d start a new section wherein I’ll alert everyone to some cool reading material you can easily access and learn from.

This week is the first!

As mentioned a couple of weeks back, there is nearly no research done and applied from petite anthropometry data, and that data is what is needed to form an accurate and appropriate sizing standard. Some of the papers that do exist on the topic are from graduate level students. One such is an exploratory study by Lisa Barona McRoberts for the Louisiana State University titled “Petite Women: Fit and Body Shape Analysis“. In her opening abstract, she states that”[f]igure type analysis of the sample indicated that most subjects were outside the industry silhouette definitions. None had the industry standard hourglass figure.” (pg vii). I’d recommend you read over her paper: it’s written in a very accessible way, and is filled with great information like a review of the literature to date.

Fun Facts from her paper

  • 47% of the women in the United States between the ages of 20 – 49 are petite.
  • SizeUSA was created by TC2 primarily to create a new sizing standard for ASTM and private clients (thus restricting the disclosure of the data and results, ie: I can’t share all the data with you!)
  • “Despite the large percentage of petite women between the ages of 20 – 49 in the US, the sector has been largely overlooked. With the Latino and Asian population increasing throughout the country smaller sizes are needed”. (pg 17)
  • As a side note: SUPER interesting data from the CDC (PDF): they have charts filled with anthropometric data that show percentiles for all  measurements and separates out data from individuals from different races. They oversampled individuals “60 and over, all Hispanics persons, black persons, and those with low income to improve the precision of the statistical estimates for these groups.”  (pg 1)
  • According to the Standardized Pattern Measurement Chart for Women by Brackelsberg and Marshall from 1994, Misses’ petite sizes are 3/4 – 1 inch shorter between the back neck and waistline and 1/2 – 1 inch shorter between the waistline and the hipline than the measurements provided by the misses’ patterns. (pg 25)
  • The study conducted for McRoberts’ paper consisted of 52 petite women, 5’4″ and under, ages 20 – 49, taken from a metropolitan centre in the southeastern USA. They took a variety of measurements.
chart
from McRoberts paper, pg 30

 

 

The above chart is simply the data from that PS 42-70 standardization chart we talked about last week. The chart below is a comparison of the data from McRoberts’ study and the petite data from PS 42-70:

chart
from McRoberts paper, pg 45

Check that out: they found that the voluntary product standard and sample mean numbers showed significant differences in back neck to waist length. And, as McRoberts states, the back waist measurement is one of the most important measurements!

Fun Fact

Why is it so hard to find petite sizing in modern sewing patterns? According to S. P. Ashdown et al in their paper “Sizing for the home sewing industry”, comparing a misses regular size 14 and misses petite size 14 shows relatively minor measurement differences, so pattern making companies generally do not make petite patterns today. Note: this is information from sewing charts, which is taken from all that old data! Let’s hope computer assisted design and body scan technology help to update this, so the idea of petite bodies can have a greater place in our craft industry!

Question

Do you sew? Did you notice the lack of petite-specific designs today? Do you think separate, petite sizing should be reinstated based on new data?

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#KnitPetiteProject: How is the standard for petite different than the standard misses/women?

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