I used the Edding Filler available here in Italy through amazon/ebay.
For best results the engraved text should be 0.6-0.8mm deep and 0.5-1mm thick.
The process is very easy:
- Carefully sand the surfaces of the part using sandpaper&water. You want to have fairly smooth finish on flat surfaces were the text lies, otherwise the wax marker will highlight crevices and 3d-print layers.
- you can use use masking tape to protect the areas far from the text to be marked
- Wipe the tip of the engraver filler across the part, so to completely fill the engraved text using with the wax.
- wipe off the excess of filler on the surface using a paper towel (remove the masking tape if you used it). If you are using a non-permanent marker you've finished. Otherways you need to complete an additional step:
- let the wax dry for a couple of hours then sand the surface with a fine grit sandpaper in order to achieve a clean finish.
I've tested the process with my 3d printed handles using Edding 950 markers, pls see the pics (the last one is from my actual cheapo saitek-based TQ). The result is permanent and quite satisfying: