After noticing that dust tends to accumulate on the fan's "petals", I decided to make two fan guards for the extruder fan and for the X axis motor fan, with my logo on them.
After printing, I painted the logo and one of the circles with acrylic paint and a gloss transparent finish.
This guard fits a 40x40mm fan.
I printed mine in white PLA, with 0.2mm layer height and concentric infill.
After printing, please note that you will need longer screws or bolts to mount the guard behind the fans.
Also, you might need to introduce very thin washers between the fan and the guard, to allow for more room for the fan to turn.