Please note that articles are sent to your location from Spreadshirt's fulfillment center which is outside Switzerland. Depending on your location, large purchases may cause custom fees. In our tests, ordering one shirt didn't trigger additional fees.
We will donate all our earnings (a fraction of the article prices) to the Humanitarian OpenStreetMap Team HOTOSM. HOTOSM is a charitable NGO that acts as an interface between OSM and humanitarian organisations such as the Red Cross or Médecins Sans Frontières. Read more about it here and here.