Top: sketch of a simple atmospheric model capable of producing 3LPs in penumbrae at disk center (panel a)) and larger heliocentric angles (panel b)). B₁, B₂, v₁ and v₂ represent magnetic field strength and velocity in the lower and upper atmospheric layer. The LOS is parallel to the local vertical z at disk center and seen under the projection of Θ for increasing heliocentric angles. Middle: Hinode-SP intensity image of a sunspot at disk center (panel c)) and off center (panel d)). Regions with 3LPs are indicated in red, and regions with RPPs are shown in blue. Bottom: same as above, but for GRIS observations. The black and white contours indicate the penumbral boundaries, and the white arrow points to the center of the solar disk.