The surface of your 3D printed model is defined by the material and technology. In addition, the number of post-finishing steps also determines the cost and quality of your High Detail Resin model.
The natural surface of your High Detail Resin model is perfect if you just want a physical model in your hands. You get to see and feel the basic material your model was built from. High Detail Resin models will always be smoother than powder based models (e.g. Polyamide).
High detail resin is a photopolymer material cured by UV light immediately after it is jetted. This results in fully cured models that can be handled and used immediately, without post-curing.
The gel-like support material, which is used to support complicated geometries, is removed by water-jetting. So basically, your model is printed, cleaned up and shipped to you.