Someone recently wondered why they were losing details on their prints that they were making with their FDM printer. To be fair, the best way to get really good details in 3d prints is to use a resin printer. They are just better at it. However, if your situation dictates that you use a FDM printer, there are a couple of things that you can do to get a little more detail from your prints.
First of all, reduce the layer height. Many slicers have a default layer height of 0.2mm. This means that you will definitely be able to see the layer lines and lose a significant amount of detail. Each machine is different, I’ve found the best setting for mine to be 0.08mm, but you should experiment with different settings to see what yours is. Most FDM printers are more accurate in X and Y than they are in Z, so this will resolve a lot of your problems.
Another fix that you can try is to reorient the print. Lithopanes, for example, are usually printed vertically. Even though the structure is more stable laying flat, it’s difficult to obtain the detail needed for a lithopane in that orientation.