I designed this week's shirt with my daughter.

Each week for a year, I’m going to be designing a shirt and releasing it on my Threadless store. This is the design for week 11.

My middle child, Jill, turns 10 this week. As part of my 52 Shirts project, I decided I would design a shirt for each child on their birthday.

It was easy to choose what to design for Jill. The girl is obsessed with unicorns. So I designed a unicorn the way I would design a unicorn. Angular and modern.

To be honest, it completely sucked.

And that’s when I had an epiphany. Instead of designing a shirt for Jill, I needed to design a shirt with Jill. I threw out my crappy unicorn design and started to talk to Jill about what she really wanted in a unicorn shirt. We sketched together at the dining room table. We talked about colors and style. She taught me all about “kawaii” style (which apparently is Japanese for cute). We drew different versions of kawaii unicorn eyes. And the end result — our “Team Rainbow Unicorn” shirt — is one of my favorite creations ever.

(One fun note, the horn has ten segments because she’s turning 10. That was my wife’s idea. This shirt is a complete team effort.)

I’ve always said that I don’t — that I can’t — design cute things. And yet, this unicorn is completely adorable. I could never design something like this on my own. I needed Jill’s help to break out of my rigid style. It’s just another reminder to me that I’m a better designer when I partner with other creative people.

The “Team Rainbow Unicorn” shirt is available on Threadless in a variety of colors and styles. Hope you think it’s a cute as Jill and I do. And happy birthday, Jilly!

Bob Wertz writes about design, technology and pop culture at Sketchbook B. Bob is a Columbia, South Carolina-based designer, creative director, college instructor, husband and dad. He’s particularly obsessed with typography, the creative process and the tools we use to create. He's currently in the middle of a project to design a new shirt a week for an entire year. Follow Bob on Twitter, Instagram and Micro.Blog.