To choose the correct trademark class, you must decide whether your trademark applies to a good or a service. A good is a physical item that people purchase from you. A service is an activity that you perform for other people. Sometimes, itâs easy to tell the difference. Furniture, for example, is a good. Accounting is a service.But other times, the line isnât so clear. The Trademark Office uses the example of T-shirts. If you have a bunch of t-shirts and you sell them, you are providing a good. If people bring shirts to you and you custom print them, you are providing a printing service. If you sell t-shirts and also print designs on them, you may need to register trademarks for both a good and a service. And if you have a website or retail store where you sell t-shirts or other goods, you are providing a retail service.