"Everyone thinks that I'm a miserable bitch who goes shopping every day," the Daily Star quoted her as telling a New York fashion magazine.
Posh added: "When you are well-known in the tabloids and you're trying to break into a new industry, it makes it very difficult. People get preconceptions. It's hard to change people's thinking, which is what I've set out to do."
The 34-year-old has now vowed that she won't let her reputation damage her label, DVB. She said: "I feel really charged and ready to go. I've waited a lifetime to do this."