Prof J starts his own clothing brand which he calls Greenious and he focuses on jeans and t-shirts. The idea is that all his clothing is super environmentally friendly, it's all organic cotton, zippers made of recycled metal, recycled polyester, etc. He mostly sells to hippie-dippy boutiques that sell eco-fashion to ethical hipsters. He registers his trademark at the USPTO. After 5 years he has customers in about 12 states, all the hippie-dippie states like Vermont and Colorado and California, etc., plus New York. In the 2nd year of business he comes up with a signature design concept: he puts a little green metallic thread somewhere on each item (the thread is made of a recycled polyester fabric). The green thread becomes a distinguishing characteristic of his line. In this 5th year of business, he sees that another eco-fashion brand, Sassifrass, is also selling organic cotton jeans and they are also including a snippet of metallic green thread similar to the one on Greenious items. The only difference is that they put the green thread on the seams and on the bottom hems, while Greenious tends to feature them on the back or front pockets. Prof J is so mad that he goes out and drinks a whole bottle of organic mezcal and he drinks it with some organic limes! Then, after recycling the bottle, he rides his vegan skateboard over to his lawyer's office. You are his lawyer. Analyze Prof J's legal options.

What will you tell him? What legal concepts will you try to make sure he understands?