In my previous post, we saw how horizontal stripes don’t necessarily make you look wide. That’s because they can lead the eye up and down the figure, making it appear taller.
When something looks taller, it also looks narrower – so horizontal stripes can help you appear thinner.
But how can you tell whether your striped top or dress will have the desired effect? Well, there are two key principles to understand and apply to your body type.
Principle #1: Horizontal stripes improve depth perception
Horizontal stripes actually make it easier to tell exactly how wide (or deep) an object is.
You can see the effect in action when you compare these two identically-sized torsos.
Source: Thompson and Mikellidou 2011.
So if you want people to know exactly how wide your waist is, it makes sense to wear horizontal stripes. They make you look taller and emphasize a narrow waist.
Vertical stripes, on the other hand, have two disadvantages: they lead people’s eyes across your figure (making you look wider), and make it harder to tell how narrow your waist is.
Principle #2: How big your waist appears is how big YOU appear
When we look at someone, we don’t take in every single thing about them at the same time. We tend to treat someone’s waist size as a particularly important piece of information about their overall size.
If your waist appears small, we’ll assume the rest of you is slim too – even if your arms or legs are disproportionately heavy.
Let’s combine these two principles and find out what they mean for different body types.
Slim Waist: Triangle, Pear, and Hourglass Body Types
If your waist is relatively narrow compared to your shoulders and breasts (making you a triangle shape), hips (pear shape), or both (hourglass shape), then you can make people think you’re skinnier overall by highlighting the narrow width of your waist.
Source: What Would Taylor Swift Wear?
So you would want to wear horizontal stripes on something tight-fitting, to make your slim waist as noticeable as possible.
Thick Waist: Apple and Rectangle Body Types
If your breasts and hips are barely wider than your waist (making you a rectangle shape), or your waist is disproportionately thick compared to your slim limbs (apple shape), you’ll want to camouflage your waist size so it’s harder for people to tell exactly how thick it is.
Source: Lyst, Rag & Bone Ash striped top.
You should wear horizontal stripes on a top that’s loose and square-shaped, giving you a cute, blocky appearance on top. You could also highlight your long legs with skinny jeans or a miniskirt.
That way people will just assume your waist is as slim as the rest of you, proportionally; and the stripes will add an illusion of height and slimness.
A Note on Boob Size
If you have big boobs, remember to choose a low-cut top, or else the horizontal stripes could make you look even more top-heavy.
NO: Crew neck
YES: V-neck or Scoop
Boatneck Tops: Good for Just About Everyone
A Breton/sailor-style boatneck top that’s not too loose and not too tight will give you a casual French gamine look. This works for any body type, as long as your boobs stick out further than your stomach.
Note that the sleeves should be simply cut and horizontally-striped all the way down; sleeves with different stripe directions can tend to make your shoulders look broader.
If you’re fat, you may think you should never wear horizontal stripes or you’ll look even fatter. But you would be wrong, because they make you look taller when worn on loose fabric.
If you’re skinny, you may also think you should never wear horizontal stripes or you’ll look fat. But you would be wrong, because they make it easier to notice your small waist, especially when worn on tight fabric.
 Beck, D.M., et al. 2013. “A new illusion of height and width: taller people are perceived as thinner.” Psychonomic Bulletin & Review 20 (6): 1154–60. DOI: 10.3758/s13423-013-0454-8. https://link.springer.com/article/10.3758%2Fs13423-013-0454-8.
 Apparently we perceive depth best when the surface pattern runs parallel to the maximum curvature of the object. Since the human body tends to be curviest horizontally (at the hips, for instance), horizontal stripes should give the most accurate information about its depth. (This is my paraphrasing of the summary given in the paper I cite in footnote 3.)
Li, A. and Q. Zaidi. 2000. “Perception of three-dimensional shape from texture is based on patterns of oriented energy.” Vision Research 40 (2): 217–242. DOI: 10.1016/S0042-6989(99)00169-8. http://www.sciencedirect.com/science/article/pii/S0042698999001698.
 Thompson, Peter, and Kyriaki Mikellidou. 2011. “Applying the Helmholtz illusion to fashion: horizontal stripes won’t make you look fatter.” Iperception 2 (1): 69–76. DOI: 10.1068/i0405. http://pubmedcentralcanada.ca/pmcc/articles/PMC3485773/;jsessionid=897EA2A24E95F58DB902A2108B258F05.thrasher?lang=en-ca#R7.
*This article is also the source of the featured image for this post.
 Cornelissen, Piers et al. 2009. “Patterns of eye movements when male and female observers judge female attractiveness, body fat and waist-to-hip ratio.” Evolution and Human Behavior 30 (6): 417–428. DOI: 10.1016/j.evolhumbehav.2009.04.003. http://www.sciencedirect.com/science/article/pii/S1090513809000403.