When making an injected molded part, you are limited by the capability of molds because molds are made out of metal. So you can only create the finest detail that your machine can make in a metal mold. For the most part, this process can create fine details but there are some limitations.
On the other hand, with 3D printing you can create very complex shapes with ease. There is no need for a mold or added machinery costs. The part is grown by a 3D printer the same way as it creates every other product. Some of the most complex looking products can actually be some of the easiest designs to produce. For example, in this pyramid design the printer nozzle never lifts off the product because it can create this design with one continuous line. It would be virtually impossible to create this design with injection molding due to the various holes and textures this art piece has. Textures on the surfaces of complex shapes are a lot easier with 3D printing and you have a lot more freedom.
With 3D printing, textures have a wide variability because you are not designing a mold around your part, you are just designing the part. So you have unlimited capabilities of the types of textures you can create. Whatever you can do in CAD can be 3D printed, which is not the case with injection molding. With injection molding, you are unable to imprint thin texture on a part so instead you would have to add various steps to the manufacturing process in order to get your part how you’d like. Even if you are able to create your design in the end, manufacturing your product will be a lot more expensive because of this.
In short, molds are expensive. However they might be worth it if your part is simple enough and you are creating thousands of products. But be sure to keep in mind that the more complicated your product is, the more expensive the injection molding process is going to be. With 3D printing, you are able to produce more complex parts with textures because it does not create an added step. With injection molding it might. So before you start to manufacture your textured part, compare the capabilities of 3D printing versus injection molding to see which is best for your company.