As you might have noticed tube socks are not your average sock and you might wonder what they are used for. Well, custom made tube socks are mostly based for 2 purposes: sports and fashion.
When it comes to sports, they are used for team sports such as soccer, hockey, football, softball, baseball, lacrosse (along crew socks), volleyball, basketball (along crew socks) and rugby. As you can see it is quite an extensive list and regarding designs, it varies from one sport to the other; for example, ruby socks tend to feature stripe, softball socks have fun colors and logos while baseball socks are usually plain.
In terms of fashion, custom tube socks are mostly associated to the goth/punk look among girls, which means they are usually black with designs featuring skulls, etc … (you can see an example on the right).