The nets  made in copper installed by us, have a higher composition of those in polythene. These ones in fact , have a  processing with a rhombus form with a size of  2 cm.
The most frequent installation  is made to preserve the holes from the presence of fliers.
Fliers can nest with a lot of facility in those holes. The preciousness of this net, according to the application in the holes, are the following ones:

- It does not need frameworks but it is possible to cut the exact size of the spot of the hole. After that it is possible to fix it  to the edges by a resin.

- Few weeks after the installation the atmospheric factors confer a brown colour which can be easily confused with the darkness behind. In this way the net is invisible.

- It allows not to close the holes using bricks or different materials. This will preserve the historicity of their function.