Horizantal stripes flatter the figure

Vertical stripes don't flatter – they make you look fatter

Horizontal, not vertical, stripes have slimming effect

The fashion gurus have got it all wrong, claims an expert in visual perception. Far from making you look thinner, wearing clothes with vertical stripes will accentuate your girth.

Wearing horizontal stripes makes you look thinner, according to new research – contrary to widely held belief that vertical stripes are more flattering to the figure.

The discovery was presented at the British Association for the Advancement of Science (BA) Festival of Science, held in Liverpool, England, last week.

Optical illusion
While investigating variation in the architectural design of columns in the temples of Paestum, Italy, Peter Thompson, a psychologist from the University of York, came across an illusion whereby the direction of the stripes determines the overall illusion of height and width.
"It is supposed to make the columns look straighter than they actually are. You might expect these columns to be cylindrical but they rarely are," he said.
After looking into it further, Thompson discovered that this so-called 'Opel-Kundt' illusion was described by a German physiologist Hermann von Helmholtz in the mid-19th century. He found that if two identical squares are drawn side-by-side, one with horizontal stripes, the other with vertical stripes, then the square with the horizontal stripes looked taller and narrower than the other with vertical stripes.
"I found that this relates to clothing too," said Thompson. "In HelmHoltz's Handbook of Physiological Optics he noted that ladies' frocks with cross stripes on them make the figure look taller, so this idea has been around for a while."
Black is best
To test whether the illusion held true today, Thompson showed drawings of two women, side by side, to 20 individuals. One woman wore a dress with horizontal stripes and the other in a dress with vertical stripes.
After around 200 repetitions over which the body size of either woman was varied, he concluded that the horizontal stripes made the figure look taller and narrower.
Thompson found that guidebooks to temples and ancient architecture often refer to the principle of 'entasis' or the architectural trick of making a column bulge in the middle to accommodate for a wasting effect .
Despite his investigations, he concluded that wearing black is still best for flattering the figure and ideally, "black with a few horizontal stripes."