This is called a trademark. There are manufacturers that specialize in making trademarks. They provide the pattern or pinyin sample they designed to the manufacturer, agree on the price, sign a contract, agree on the rights and obligations of both parties, and resolve disputes, etc. The clothing manufacturer sews the trademark onto the collar during processing.

Don’t forget to register your trademark with the Trademark Office. If the market sells well and becomes a big brand, it will be copied by others.