If I buy rolls of fabric from a fabric store, make clothing and sell it..is that illegal?

In the UK this has been done for hundreds of years. That is the whole idea of dressmaking. You buy fabric, make clothes and sell them. You do own the fabric when you buy it. Same principle if you buy a car and sell it on, or anything else Where do you think the clothes shops get their fabric from, they do not maufacture it themselves..