Make the top surfaces of your 3D prints (almost) perfectly smooth with Cura 2.7 “Ironing” setting

As a long time Cura 2.x user, I was excited when I read in the Cura 2.7 Beta changelog about some of the newly introduced settings.

One setting in particular, looked very interesting & promising: the “Ironing”.
The setting can tremendously help with the topmost layer surface finish when printing objects with big flat areas on top (in my test case, it was a keychain I was making for a friend). For “curved” objects it should not matter.
Here’s how it works: when the topmost layer is finished, it REPEATS it without moving the print head higher. The head moves in a more dense zig-zag pattern (customizable, default 0.1mm) with much lower extrusion multiplier – not sure if it was 5% or 10% by default, but in my test case I used 10%, and it worked flawlessly.
This helps smooth out any surface irregularities and gaps on the topmost layer, hence the name: “ironing”.

Here’s my result – same model & same settings:

Another angle:

Note that the PLA filament I used is both just a liiiittle bit transparent & has a metallic color, which makes any top layer irregularities a lot more visible – especially when the print head finishes one are, goes to another, and then comes back to close the gap between the two areas.
Actually, the surface finish of the model, printed with ironing enabled, is even better than the photo. I intentionally positioned the camera in a way that makes any irregularities shine.
The same model looks better when printed with other colors, although the actual surface finish on touch is the same.

OK, so how do you enable this setting? Easy.
First, and this is mandatory: make sure you are running Cura 2.7 Beta. You can download it from here, by clicking “Download Cura 2.7 (beta)”.

The setting is located in the “Experimental” section, and it’s hidden by default.
To make it visible, you have to scroll down to the “Experimental” section, hover the mouse over the section title, and click the gear icon: