Demographics Part II

If you’ve been following my Demographics postings you’ll know I’ve been searching for linear (and non-linear) trends in sizing so as to see if there really is a trend of any kind that can be used to improve the way we not only make patterns, but also in how we interpret the sizing interval for ready to wear.

Historically speaking ready to wear sizing has been arbitrarily set based on 2 inch increments of bust size. In Australia we use 4cm increments (5cm would have made things a little universal perhaps, but a tighter increment does tend to provide a better fit). As cup size changes irrelevant of other body dimensions, I find bust a really stupid system to use for determining size increments. I prefer to use underbust as the principal reference measurement … which should be practical for women as this is also how bras are incremented. Using underbust means I have something that relates more realistically to the other horizontal measurements. I tend to use nape to waist as my vertical reference measurement as I get equally realistic relation to other vertical measurement. This is important. When we chart out the main body measurements as a function of underbust and start to apply the linear and non-linear relationships from the graphs in my last post you get something like this (using Australian sizes) … note: these are projected increments in centimeters …

The above table can be considered as representative of the global population as a whole and is extracted from a sample size of over 27,000 measurement sets.

Now all this assumes a fixed increment in underbust. But let’s take a look at the percentages for a moment. Using a linear increment creates a new problem … one in which the quantity in each fixed size is different. Is it possible, or even helpful, to create a size increment which would have the same percentage in each size or at least a more even distribution? Why might we even consider this? 

With the current sizing system, manufacturers cut ten times as many size 10s as they do size 20s, for example, so they can accurately meet market demand … or at least that’s the theory. Because of the low 3.7% chance of selling a size 20, many retailers won’t order the size for general sale, leaving such sizes for the plus size specialist retailers. The same really applies to size 18 … and above in general. But if we were able to accurately fit a current size 20 with a new size that spread across, say a 10% interval, perhaps it would become more viable to carry such sizes?

There are many reasons why it isn’t done besides the obvious “we don’t want to change the system everyone knows”. The increase in shape variation in larger sizes means more ease (or less negative ease for swimwear) is used to increase the size envelope, but we’d need even more if we were to spread across a greater range. This means that while we’ll get a broader size envelope, we’ll compromise on fit. However this may be construed as “small size” centric thinking … or seeing the larger size as the problem rather than the solution. You see, the problem with larger sizes is the variation in shape within each size … or better said, the advantage of smaller sizes is the lower variation in shape with each size. Have I lost you yet? Consider for a moment what would happen if we made size 10 and size 12 just one size group. Because smaller sizes are easier to fit and have less shape variation, it would be much easier to mess around with those sizes than with the larger ones …. indeed if we widened the envelop on the smaller sizes and had less of them, then we might be able to afford the luxury of closing the increment on larger sizes and thus improving fit with respect to shape variation. Of course splitting up a small increment of 3.7% is also somewhat stupid, but if we looked at opening the increment on sizes 12 and under, and widening up 14-18 we might be on to something.

This is of course more a matter of food for thought rather than something that is likely to be considered in manufacturing. Uneven increments would be hard to explain (I’m having trouble explaining it myself)  and manufacturers wouldn’t want to potentially compromise 90% of their market for the sake of helping 10%. The point of this exercise is to get people to consider why the existing size increments are what they are and where the population is distributed through that range. 80% of the market is in the small to medium sizes, 10% in the large and 10% in the plus sizes … this is why things are the way they are. If the plus sizes made up 80% of the market then the whole sizing system would be different to the way it is now … I don’t care what the politically correct people say … the industry is trying to satisfy those who pay the bills and not those who experience the greatest difficulty in getting a good fit.

This is really a fairly meaningless exercise but students should list as many reasons as they can for and against changing the size increment system for ready to wear that we have at present (there’s many more than mentioned here), try to demonstrate in pattern making terms why change might be beneficial, and be able to suggest at least one alternative system.