Pathio Users

Implement Ironing/Neosanding

Suggestion Summary

Ironing/Neosanding (coined from the inventor, Neotko) is a means of running an under extrusion pass over an extruded surface layer. By extruding at a low multiplier (between 15-20% flow), via a hot and fast tool pass (typically I use 100mm/s) and not changing the z-height, the second, under extruded pass fills gaps between the original tool path of the top surface, creating a VERY smooth, even top layer.

Example image, from Neotko:

This may not be desirable for all prints, but for prints that have minimal Z height, or large flat areas in the XY plane, it can massively increase the quality of a print for the minimal extra time taken.

Why is this useful?

Achieve injection moulded like smooth surfaces on flat model surfaces parallel to the buildplate, greatly increasing the model aesthetics.
May also improve model’s real-world watertightness, by sealing holes between paths.

  • Do other slicers do this?:
    Cura has implemented ironing as an experimental feature which is a good proof of concept. It has several flawed aspects sadly. From reporting several bugs/feature requests with it directly to the Cura devs, there is (what appears to me to be) a general unwillingness to improve it without community code contributions or external plugins to post process the gcode.
    You can implement ironing in Simplify3D via custom processes.

Screenshots/Supporting Info


Hi Chompworks,

I definitely see the use in implementing this. I really do like using it when I’m occasionally printing with cura.

Thanks for the feedback and do let us know if you have any more suggestions!



Not a feature ive used, but when mentioning this slicer to my dad this is the first thing he asked if it has.

1 Like

For what it is worth, Cura did not develop Ironing, a simplify3d user pioneered this technique, and requested that Cura include it, which chtey did, because they do listen to thier community pretty well.

Regardless, the user who pioneered this method is open to others using it, so long as they provide attribution i suspect.


1 Like

In my original post, you’ll see that I mention Neotko several times. He’s a friend on Twitter.

Originally, as you state, this process was pioneered by Neotko in S3D. However as that is a custom process that you have to essentially make from scratch following his instructions, I namechecked Cura first as the more “mainstream” implementation.
But when the Cura team added Neosanding, they renamed the feature from the original name to Ironing, and was called out for not giving Neotko any credit. That is all archived and still visible on the UM forums.

You’ll also see that Cura have implemented it, but are unwilling to change details of the implementation despite the flaws that myself and other users have pointed out to them - (feel free to check my feature requests on their Github issue tracker and their responses suggesting rather than them changing the underlying code or exposing additional variables to the user, that I write post processing plugins for the features to achieve the same result).

So I stand by what I said.

I didn’t disagree with you on any level…

Cool. Thanks for the confirmation of that.


i have a few ideas based on neosanding which i actually talked with Neotko on facebook before.

  • reverse ironing - which iron the first layer to ensure it the first layer is squeezed down enough to eliminate or minimize the extrusion gaps/create mirror finish on first layer. it can also serve to improve the first layer adhesion to the bed.

  • iron every layer to improve layer adhesion and transparency (of low opacity filament)


I’m not sure ironing the first layer will help adhesion. In fact, if you have bed adhesion issues, the drag of the ironing/neosanding may pull the print loose.

Regardless, the technique for the top layer has my support!

In fact, if you have bed adhesion issues

squeezing down the first place will definitely improve adhesion, the thing is there are many type of bed adhesion issues. if your print cant/barely stick at all even for the first layer, then the improved adhesion will not help at all. there are situations like ABS, where you will definitely see the wrapping decrease/nullify by ironing the first layer.

+1, that would be a great feature!

1 Like