I think it is necessary to look at the purpose of your model design. If the product is novel and has certain practical value, you can apply for an appearance patent or utility model. This can not only reflect the value of your design products, but also bring some profits. The way to apply, you can go to the patent office yourself or find a professional agency. Because it involves the writing of technical disclosure, it is recommended to find an agency to handle it, so the success rate is relatively high.
Adopt it