Superman wears alien armor for protection. Batman wears Wayne Industries armor for protection and to make criminals think that he is beast. Wonder Woman wears Amazon armor. Green Lantern's suit is an energy-based uniform for an intergalactic police force. Aquaman wears Atlantean armor. Cyborg's suit is part of him.

The point is that there's a logical reason for wearing their suits and for where their suits come from.

I understand that Barry may want to protect his secret identity, but where did his costume come from? Why does he wear it instead of a ski mask? Did he just slap it together in his apartment? Does it provide him with any physical protection or does it just look cool?

I believe it's made of materials that can withstand the high speeds at which he runs.

So he can look like all the other super heros on Earth at the time. And I'm assuming he's still a police scientist with a chemistry degree, so throw in some comic science for the origin.

@Captain13 said:

Did he just slap it together in his apartment?

Yeah, I wonder who made it....

What TheCommissar said. During the Silver Age stories Barry created the suit as a homage to Jay Garrick (the Golden Age Flash) and designed it to withstand the heat and friction it would encounter as he moved at super-speed (this was before the writers added in the speed force aura that protects speedsters from things like that). He also bathed it in a chemical compound that would allow it to shrink and expand so he could store it in a hollow ring.

When Wally became Kid Flash he basically got the same costume but over time writers brought in the idea that a speedster could create their costume using energy from the speed force (sort of like of Ms. Marvel, now Captain Marvel, from DC can manipulate matter enough to turn whatever she's wearing into her costume and back again). So from that point on Wally's costume was pure speed force energy and its design could be redone should he desire (such as closing the mask around his mouth when in a gaseous area). He taught this technique to all the speedsters just before Flashpoint.

Since the new 52 began it looks like writers wanted to go back to the idea of Barry keeping the costume in a ring (which I disagree with and think they should have kept the speed force costume as the new armored look would have made a lot more sense being composed of energy that Barry mentally manipulates into a form rather than somehow storing it in a small ring like he could when it was only clothe/spandex-like material).

So yes, part of Barry's costume is armor to bolster his defense but the other part of it is wearing something that can survive his super-speed. He is also the creator of his costume and always has been.