WHY ARE SOME MODELS NOT PRINTABLE?
There’s a fixed-size nozzle that you can use to precisely print very fine details. If you often print subtle details, this will be a problem you often encounter. There are several options that allow you to successfully print this subtle detail. Next, we introduce one by one how you can print the model.

Redesign a thin-walled model
The most obvious choice is to redesign your model to include only features that are larger than your nozzle diameter.
Usually this involves editing a 3D model in a CAD file to modify the size of the subtle features. After you increase the thickness of the subtle feature, you can re-import the model into CURA to check if your printer can print the 3D shape you created. If the feature is visible in preview mode, the printer can print the modified feature.
Install nozzle with smaller opening diameter
Most of the time, you can't directly edit the original 3D model. For example, it can be designed by other people or downloaded from the Internet.
At this moment, you need to consider the second nozzle for your printer to print subtle features. In most printers, the nozzles are detachable, which makes it easier to adjust after the purchase. For example, you can buy a 0.3mm and a 0.5mm nozzle at the same time, so there will be two options for you.