Editor’s Note: Jude Stewart, Print’s color expert, is devoted to Imprint so much that she created a backlog of posts in preparation for her maternity leave. I’m pleased to report that Jude’s ‘lil guy has since made his debut. Mamma and baby are doing well.
Consider the following conundrum: If we accept the prevailing fashion-rule that horizontal stripes make you look fatter, why in tarnation must so many maternity clothes feature horizontal stripes? Am I the first to blow the lid off an exceedingly cruel conspiracy?
As a pregnant-mama due in early August, the question has plagued me particularly in recent months. The conundrum only deepens when you cave and buy some stripey maternity wear, out of sheer lack of competing options. I expected to resemble a bursting circus-tent as my girth expanded, yet strangely — mercifully — the opposite was true.
Now at 37 weeks, I wear horizontal stripes four days out of five, and they only lend my big-as-a-house-ness an increasingly cute, buoyant quality — a double-amazing illusion, given how not-cute, not-buoyant one feels in that final stretch.

Me, pregnant in horizontal stripes at 30 weeks
What gives, fashion world?

Stripes on stripes on stripes by Cameron Russell on Flickr: http://bit.ly/119Y7Cv
Let’s delve into the research on this pressing question, shall we? In 2008, perception expert Peter Thompson of University of York embarked on a study comparing the visual effects of horizontal versus vertical stripes. (Originally he was investigating variations in the architectural design of columns in the temples of Paestum.) The Guardian describes his experiment:
“His test involved showing pairs of pictures of women to volunteers. In each pair, one woman was wearing a dress with vertical stripes and the other was wearing horizontal stripes. In each pair the vertically striped figure was the same woman, but the horizontally striped figure was either slightly fatter or thinner. The subjects had to choose which they thought looked more rotund.”
The results? The vertically-striped women had to be 6% slimmer before they were judged equally wide as the horizontally striped women. When the women were actually identically sized, the horizontally striped women appeared thinner to the volunteers.
This so-called “Opel-Kundt” effect was first described by German scientist Hermann von Helmholtz in the mid-19th century. In it, he compared 2-D squares, one vertically striped and the other horizontally striped. In his own experiments he found most respondents saw the horizontally striped square as taller — even though both squares were identically sized. The effect was so persistent, in fact, von Helmholtz argued in his Handbook of Physiological Optics that ladies’ frocks should be horizontally striped to accentuate slenderness and height. These articles in Cosmos Magazine and the Telegraph tease out more optically useful tidbits.

Stripes by Daniel Petzold Photography on Flickr: http://bit.ly/18z054R
The plot thickens when you start thinking in 3-D about stripes. Here I direct your attention to ionpsych.org, a joint project among psychologists at the University of Illinois. Contributor Audra Lustig takes the maternity-stripes conundrum to its next logical question:
“The main problem with applying Helmholtz’ theory to clothes is that people are not 2-D rectangles. People have curves and depth cues that interact with vertical and horizontal stripes in tricky ways. For instance, strong 3-D cues make objects look thinner (Taya & Muira, 2007).
Observe:

In this figure, the vertical stripes are altered until they make the fatso 2-D square look like a fit 3-D cylinder. The authors claimed that the same thing happens when people wear vertical stripes; the stripes are slimming because they accentuate depth cues from the body.” Lustig then recaps her own experiment comparing images of women in horizontal stripes rendered with 3-D effect, versus women in vertical stripes that looked 2-D flat.
Again, the horizontal stripes were judged the skinnier. This jives with my own observations: a fitted shirt of horizontal stripes made my belly look fitter, more dynamic, and clearly not the result of indiscriminate Ho-Ho’s consumption.

Stripes on Stripes by Dominic Alves on Flickr: http://bit.ly/1bXpIek
Mysteries still remain, like: How did collective amnesia take hold and erase von Helmholz’s brilliant fashion discovery a century-and-a-half ago? I also wondered how Prof. Thompson convinced his subjects to overcome a deeply entrenched bias to “see” the horizontally-striped person as the wider one. As the frivolous findings of patterns-science march onward, know that this Print contributor will boldly soldier on with them!
This post also provides me with an excuse to explain my absence from Printmag.com August through September. We’ll be welcoming our first child, a baby boy named Lev Henry, during that time. Stay tuned for continued color- and pattern-chat coming at you in October!
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