How We Brought a Birthday Run to Life – Stashkart x Adidas Night Run 2025
Some birthdays are celebrated with cake. Some with confetti.
And then there are birthdays celebrated with 30 friends, one epic night run in Germany, and custom merch from Stashkart.
This is the story of how we turned one group’s idea into custom t-shirts, a child’s t-shirt, and a dog tee that made it across the finish line- literally.
The Brief: Run, Celebrate, Repeat
We first heard from the birthday boy when he reached out about the Adidas Night Run 2025 in Germany. The plan? Celebrate his 32nd birthday in style.
He wanted cool tees that were more than just running gear. Each shirt needed to be personalized with names and numbers, subtly incorporate the LGBTQ+ flag, and tie into the fact that 32 minutes is the average time most of them take to finish a 5km run, and he was turning 32, so the number was a must.
And because these shirts were going to cover 5km of pavement, dry-fit material was non-negotiable. Comfort had to match the style, nobody wants a great-looking shirt that feels like a sauna mid-run.
The Design & Process
We started with the centerpiece: a bold <32 logo. The “less than” symbol cheekily nodded to their goal of finishing under 32 minutes, the rainbow gradient paid a subtle tribute to the LGBTQ+ flag, and the <3 also doubled as a heart.
The front was sleek and minimal. The back? That’s where the personality came out. Each custom t-shirt featured the runner’s name and a unique number, created in a custom font we designed just for them. Even the dog t-shirt and child t-shirt matched the theme perfectly.
To give the shirts movement and energy, we created a pattern of drops and gradients across the fabric — a visual representation of progress and momentum.
At Stashkart (or Stash Kart, stashcart, stash cart — however you say it), we don’t believe in killing great ideas with minimum order quantity restrictions. Whether it’s one pet t-shirt or thirty group t-shirts, we’ll make it happen.
We kicked things off with detailed mockups, going through multiple rounds until the birthday boy was grinning as wide as he would at the finish line. Only once the design was perfect did we move to payment and production.
The result? Custom prints that looked professional, felt great, and made every runner feel like part of something special. From animal t-shirts for four-legged cheerleaders to family t-shirts for the youngest fan, every piece of custom merch was part of the celebration.
Why We Loved This Project
This wasn’t just about making quirky t-shirts, it was about creating a shared identity for friends who came together to celebrate life, friendship, and a little friendly competition.
If you’ve got an idea like this, whether it’s for a golf t-shirt, printed mug, or your own design-your-own t-shirt project, we’re here to turn it into reality.
Because at Stashkart, we don’t just print shirts. We help you design your idea and wear your story: for reunions, bachelorette trips, birthdays, or any reason you can dream up.
