**2.5 De-powdering**

The "de-powdering" is the activity where all the unmelted powder is removed from the fabricated part. The RF designer should conceive the device avoiding highly concave cavities (those whose only opening is very small when compared with the size of the cavity) as well as minimizing (if possible) the presence of siphon waveguide sections.

**Figure 3.** *Different approaches to increase the stability of elongated structures. The orange arrow indicates the printing direction.*
