When I was in middle school, I really wanted this Nike T-shirt. It said “Just Do It,” in big black and red letters up the front and down the back, and I thought it was just the coolest. I vaguely remember someone I admired wearing one just like it, and I clearly remember all the cool kids at school having them. In fact, I can clearly recall all the cool kids having Nike shirts, and Umbro shorts, and Adidas shoes (Sambas, if I remember correctly). They all dressed like they were going to/coming from indoor soccer practice all the time.

As I started to work in Brand Design, and learn more about marketing, I remember thinking that the real brilliance of Nike’s brand was not the performance or aesthetic qualities of their products; but that they had convinced the world, through associating their brand with top-performing athletes (and therefore the cool kids who wanted to be just like them), to pay them for the privilege of advertising their brand on our bodies.

In the 1990s Nike’s brand was so pervasive that all you really had to do to mimic it was set some type in Futura Bold Condensed, and you were off to the races. Come to think of it, that probably explains a lot of my font choices in college…but I digress.

I think about this every time I see design recommendations based on, or that heavily leverage, someone else’s Design Language and/or Front-End Framework; which happens a lot. I’ve worked in companies that choose to build on top of Bootstrap, or Material Design (or both, and have a turf war over which is better). I’ve worked with designers and developers who refuse to break a rule set forth by Apple’s or Microsoft’s Human Interface Guidelines. I’ve advised entrepreneurs who have tied their brands so closely to platform conventions that you would never know that their iOS and Android versions are the same product.

This leads me to my point…

There’s great danger in using someone else’s Design Language/Front-End Framework/UI Components in your product interface. It is often overlooked by proponents of such shared frameworks that those things are equal parts User Interface Convention and Brand Expression. When you use them, sure you get the benefits of a tried-and-true UI component (probably saving yourself time and money and risk), but you also extend Google’s, or Twitter’s, or Apple’s, or whomever’s brand expression into your product at the expense of your own.

There are, of course benefits to using these things, not just in the time and money you save not having to build them yourself, but in Usability. Platform conventions are a valuable thing. If you want your product to feel familiar, and align to the choices they already made by choosing that platform, you should follow them. Universal (or nearly universal) patterns reduce the amount of cognitive energy users need to use your interface, and that’s generally good. Your designs should acknowledge Jakob’s Second Law.

Like many things in Design, the goal should be to strike the right balance between competing goals. In this case, between making things familiar enough that they’re easy to use and expressing enough of your own brand that people can tell the difference, and you can build brand equity through the interface.

In this way shoes might actually be a good metaphor. It’s pretty rare that a shoe comes to market that makes you confused about how to use it. They all have pretty straightforward design conventions and that makes them easy to use. But, it’s also pretty rare that you would confuse the products of any of the major brands with one another, because they all have unique brand attributes that help us differentiate them from one another. This is how your experiences should be designed as well.