In a method for manufacturing a three dimensional object by extrusion based modelling, tracks of modelling material are deposited in slices by a printhead connected to a three dimensional positioning system. In each slice a plurality of first tracks of three-dimensional modelling material is deposited by the printhead under a first pressure, wherein the first tracks are spaced apart so as to leave a gap between them. A second track of three-dimensional modelling material is deposited by the printhead in each of the gaps between the deposited first tracks under a second pressure, which is higher than the first pressure, such that the gaps are filled entirely. A monolithic body is formed by depositing the modelling material slice by slice. In at least a body portion of the monolithic body a pattern of first tracks and second tracks is deposited, in which the number of tracks that is deposited is increased within at least a section of the slices by depositing at least one additional first track and at least one additional second track.