Here's an easily printable PCIe single slot cover for a PC case. I altered the honeycomb pattern slightly to accommodate the variants I wanted to make, so I provide the basic cover with no cable management stuff as well.
Inner Channel:
A series of plastic tabs on the inner side of the slot cover can be used to run a cable along. I made this so that I didn't need to use cable ties and cut them every time I upgraded.
Outer Channel:
Every now and then, I need to swap display or USB cables from the back of my PC, so that I can game on the TV. I keep the long HDMI hanging off these clips on the back of the PC, with the cable between. I have a 3.5mm and 8mm variant to suit thin USB cables and thicker display cables. These are on the outer of the slot cover.
The basic cover will need no supports if printed flat, but the inner channelled slot cover cannot be printed this way and so will need supports.
The author remixed this model.