Q: could I be reported for copyright?

A: You are asking for a complicated legal opinion, which most attorneys will not provide unless you are a client. If you would like a detailed answer to your question, please hire a competent trademark attorney.

The test for trademark infringement is "likelihood of confusion." Various factors are considered and weighed in favor of the trademark owner or the alleged infringer. Each federal circuit has its own version of the test, and most of the factors are similar, but not all.

The USPTO has its own test for "likelihood of confusion," which can be found here: https://tmep.uspto.gov/RDMS/TMEP/current#/current/TMEP-1200d1e5036.html

A: Yes, you could face legal issues since "SAD DAD" is trademarked for use on t-shirts. Using "SAD DAD CLUB" or "SAD DADS CLUB" might be considered trademark infringement because these phrases incorporate the protected term "SAD DAD."

Trademark law aims to prevent consumer confusion about the source of goods. When your design includes someone else's trademark, you risk misleading customers into thinking your products are associated with or endorsed by the trademark owner.

While adding "CLUB" or "DADS" creates slight variations, these modifications likely won't provide adequate legal protection. To avoid potential legal troubles, consider creating entirely original designs that don't use or closely resemble existing trademarks. You might want to consult with an intellectual property attorney before proceeding with your t-shirt business.