Stokes I image of 3C 84 showcasing a filamentary morphology. The colour scale is logarithmic and the units are mJy/beam. The dark green ellipse in the lower left corner shows the convolving beam size (0.17  ×  0.40) mas. Two threads are superimposed: the green (blue) one traces the filament characterised by higher (lower) flux density. Their widths correspond to the position uncertainty. The computed K-H models are shown with the continuous thin lines, matching the colours of the double helix morphology. The dotted line corresponds to a linear fit of the ridge line with the purpose of determining the position angle (PA = 4.5°) of the jet propagation. The image was turned by −4.5° to align the jet axis with the ordinate. A cutoff at ∼5 mas from the jet apex was implemented, to only include high-S/N areas in our fit.