Hi there!
Happy to hear that you'd be interested in representing GrapheneOS by wearing a shirt with the logo on it! :)
Currently, there is no official GrapheneOS merchandise. It is not something that is planned, but it is something that we could potentially consider.
It would likely have to be done via a third-party to reduce overhead.
While I can't promise that this is something we'd end up doing, I am curious: how many people here would buy GrapheneOS merch if we were to offer that as another way to support the project beyond just donations?
If you would buy some kind of merch, what kind of merch would that be? Happy to hear the community's thoughts :)