It is legal to process clothes, but as long as they are sold abroad, they must have a license. If not, it is illegal.

Article 225 of the Criminal Law of People's Republic of China (PRC), in violation of state regulations, commits one of the following illegal business operations, disrupting the market order, and if the circumstances are serious, shall be sentenced to fixed-term imprisonment of not more than five years or criminal detention, and shall also, or shall only, be fined not less than one time but not more than five times the illegal income: shall also be sentenced to fixed-term imprisonment of not less than five years, and shall also be fined not less than one time but not more than five times the illegal income or confiscated of property: 1. 2. Buying and selling import and export licenses, import and export certificates of origin and other business licenses or approval documents stipulated by laws and administrative regulations. 3, without the approval of the relevant competent departments of the state, illegally engaged in securities, futures, insurance business, or illegally engaged in fund payment and settlement business. 4. Other illegal business operations that seriously disrupt the market order. Whoever illegally buys or sells foreign exchange outside the trading places stipulated by the state and disrupts the market order, if the circumstances are serious, shall be convicted and punished in accordance with the provisions of Article 225 of the Criminal Law.