
The guidelines developed through Carnegie Mellon's Design for Wearability research state that wearable artifacts need to be designed with a humanistic form language. That is, they need to be concave on the inside surface to accommodate for the body's curves, and convex on the outside surface to deflect bumps and to stabilize the form on the body.
As I've mentioned in previous posts, I get concerned about rectangular tech gadgets that are billed as "wearable" simply because they are small, strapped to some part of the body, or hung from the neck. Yet this currently seems to be a popular design/marketing strategy.
So just for fun, and to make a not-so-subtle point, I decided to strap several common rectangular objects to a friend's arm. Hopefully the idea of wearable Elvis playing cards seems as ridiculous to you as it does to me! Tic tac, anyone?
- Thanks to my faithful model Ellen!

unfortunately it doesn't seem that ridiculous to me-- these photos just remind me of cigarette packs tucked in a rolled-up shirtsleeve, which people have been doing for decades without complaining about non-humanistic design.
i'm all for considering human factors in the design of wearable machines (of all things), but what actual observed problem are curved inner surfaces intended to solve here?
when consumers have a need (be it fashionable or functional), they'll adapt existing products within the means they have available to them, such as with the cigs in the sleeve. of course they're not complaining about non-humanistic design - they just want to look cool or have fun or do some task easier than they could before.
but what i'm talking about here is manufacturers marketing products as "wearable" just because it's a buzzword and they think they can make more money that way. "wearable" products that haven't been designed with the human form in mind will ulimately alienate consumers and dilute the meaning of the word.
i haven't observed any problems with tic tac cases or any of the other items shown here, and i certainly don't think that there's a compelling reason to curve the surfaces of these packages. but that's the point - not all products need to be wearable.