Are you printing thin parts that wind up being see-through in certain areas? 

For taller prints, it’s usually not a problem as the criss-crossing patterns from the slicer will ensure that your print is eventually filled in all the way. But for thin prints, it can be problematic to have a print with gaps in the ends. When I’m printing thinner components, I typically enable Cura’s overlap function. There is a “skin overlap” setting, as well as an “infill overlap” setting. I like to leave skin overlap at 10% and the infill overlap at around 30%. This is technically just overextruding under a different name, so you specific slicer may have a different name for it.