This is a simple window cover meant to be printed with an embedded net.
The embedding is quiet simple, first add a pause around half way through the print in your slicer. It doesn't have to be precise, as long as there are a few layers above and below the net.

While printing place the net over the print once it reaches the pause and secure/tension it with tape or magnets.

I recommend increasing the Z-Offset afterwards by a small amount and keeping an eye on it until the layer is done.

Let it finish printing and cut away the excess.

This one was made for my specific window, but it should be easy to replicate it for any size.
Window: 29.5cm x 19.5cm
Vent: 19.5cm x 19.5cm with a port for a 80mm hose