I use slic3r 1.3.0 that doesn't offer an ironing option. So I wrote my own simple script in python that simply repeats the moves of selected layers a chosen number of times but without extrusion, effectively smoothing the selected layers. After generating a gcode for your stl file with your slicer (it works with slic3r, not sure about the others), run a python script with input parameters: - yourFilename.gcode - number-of-ironing-passes - start-feedrte (in percent) - end-feedrate (in percent) - list of layer heights of layers to iron (word 'top' can be used instead of a number) The script will generate a file yourFilename-ironed.gcode as an output to be printed. In the picture you can see an example (silver PETG) printed without ironing on the left and with ironing on the right. Picture doesn't reveal much of a difference, but the left surfaces feel like a sand paper, while the ones on the right feel smooth. The example in the picture (sliced with 0.3 layer height) was processed with the next command: python ironing.py ironStairs1.gcode 2 70 50 3.0 6.0 top ** Tips and support kindly accepted here: https://paypal.me/ZigaM3 Or with LBRY (LBC) credits, through my Odysee channel: https://odysee.com/@ZigaMDIY:9 I also design on redbubble: https://www.redbubble.com/people/reintegration/shop And I promote my RB designs on Pinterest: https://www.pinterest.com/reIntegration42