The E-Flite X-Vert is a pretty cool hybrid rc plane and multi-rotor copter. You can start it from your terrace and get into horizontal flight with the move of a switch.
The X-Vert has prop guards that are light, thin and fragile. They'll probably break at one of your first flights, as it happened to me.
So, why not print some new ones, and use the opportunity to color up your model! The picture shown has prop guards in neon orange, and no stickers on the plane yet, just to show the effect.
This thing has slightly more weight than the original parts. Robustness depends on the infill and material you use.
Supports are required, the amount of infill determines the strength and the weight of the guards. I've used 20%.