Superhero Den is an indie retailer based in the States that does international shipping.
You can check out their sales page here. I nosed around a little bit more and found this excellent Batman t-shirt.
That’s an officially licensed t-shirt, and it amuses me to think of some exec at DC signing off the design. It’s a grey cotton/poly blend that comes in various sizes.
Are you collecting t-shirts or is your wardrobe maxed out? If it’s time to quickly move on without buying anything else then this teleport link will take you to a random Superhero Week article.