"Natural" is not a legally defined term on Australian cosmetic packaging, so the word alone tells you very little. What actually matters is the ingredients list: a short list of recognisable plant oils and butters, no synthetic sulfates like sodium lauryl sulfate, and — where the maker uses traditional cold-process soap-making — retained glycerin, which mass-market bars often strip out and sell separately for a profit. That last point is the biggest practical difference between a proper bar of soap and a detergent bar shaped like one: glycerin is a natural humectant that helps skin hold onto moisture, and traditional soap-making keeps it in the bar rather than removing it. None of the bars below rely on the word "natural" alone; each lists a short, checkable ingredients panel.