"Socrates" vase

pinshape

Just messing around with shapes and seeing what my printer can handle and can't handle. Meanwhile, experimenting with some shallow carvings on the vase's side. Check out that line running along the edge of the shallow carving - it looks suspiciously like a seam line! I've tried standard resolution (0.20 mm) but still have no idea how to get rid of this unwanted feature. If anyone has encountered this issue before and found a solution, any advice would be greatly appreciated.