SHADING DEVICE FOR A MOTOR VEHICLE, GUIDE RAIL, VEHICLE ROOF AND MOTOR VEHICLE

A shading device for a vehicle, having a roller blind web and a winding shaft for winding unwinding the roller blind web in an extension direction. The guide rails are arranged opposite one another and each have a guide channel extending in the extension direction, wherein the roller blind web is guided in a displaceable manner in the extension direction on opposite sides in the guide channels of the guide rail while being wound and unwound and extends between the guide rails such that the roller blind web is guided out of each guide channel along a deflection region in the direction of the respectively other guide channel, wherein the roller blind web bears on the associated guide rail in the respective deflection region, wherein in that each guide rail is configured in the deflection region such that at least partial linear contact is formed by the roller blind web.