Over his four-plus seasons as Stanford's head coach, David Shaw has developed a reputation for a certain stoic facial expression on the sideline. Very little -- good or bad -- seems to affect Shaw's outside demeanor. He's even opined about the importance of keeping an even keel amidst the heat of battle on the sidelines.

Well, it was only a matter of time before the Stanford student store capitalized on Shaw's placidity. There's a new T-shirt, the "Fifty Shades of Shaw," coming out soon.

The Stanford student store is debuting its "Fifty Shades of Shaw" t-shirt. pic.twitter.com/w1HCnUZR8n

— Do-Hyoung Park (@dohyoungpark) October 8, 2015

I asked Shaw about the shirt Tuesday, and he cracked a smile before I even finished asking the question (yes, there's some irony there).

"I've seen the shirt," Shaw said. "My wife gets a kick out of it."

The Stanford student store is currently accepting pre-orders for the shirt, but an official shipping date has yet to be announced. There's an interesting twist to the timing of the release, though: Shaw has actually become noticeably more animated on the sideline this year. Television cameras captured his energetic celebration after a Barry J. Sanders touchdown run in the Cardinal's 42-24 win over Oregon State.

"I'll be honest: I'm loosening up a bit," Shaw said. "I have to give a lot of credit to (cornerback) Ronnie Harris for that... He's expressive. He's energetic. He gets people juiced up. And last year, he did it to me. He got me riled up. I always tell the guys to show their emotions and show their passion, and last year he asked me to do the same thing."

But even if Shaw's sideline demeanor is changing, one would think that his calm face has built up enough of a reputation to ensure that this shirt sells well.

"It has all of my expressions -- or I should say my expression, singular," Shaw joked. "It's all in good fun."