Comparison of phase spiral clarity when selecting stars based on azimuthal angle (ϕ, left column) and azimuthal angle of the guiding centre or phase angle (θ_ϕ, right column), and using a Gaussian filter (bottom row) compared to not using one (top row). We can note that the right column, particularly the bottom row, has a much clearer spiral pattern than the rest. The plots show number density and number density contrast in the Z − V_Z phase plane of stars in the solar neighbourhood (d < 1 kpc) with a further selection by ϕ or θ_ϕ. The left column shows stars with 175° < ϕ < 185° and the right column shows stars with 175° < θ_ϕ < 185°. All stars have 1400 < L_Z/kpc km s⁻¹ < 1500.