Copper is difficult to laser cut, really difficult! The reason is it is very conductive and, to a laser beam, very reflective. So when we try to laser cut copper the first thing that happens is the material reflects the laser beam reducing its efficiency. The next thing that happens is the material conducts the heat away from the cut area, again reducing efficiency. All this adds up to an immense amount of power required to cut through copper - far more than for materials like stainless or mild steel.

The result of this is the edge quality is not as good as for other metals - the fact we're having to use so much power is overkill and this results in a slightly "chewed" edge effect. In addition the heat build-up in the material is so high it discolours around the cut zone. You can see both effects in the above image.

All this means we can only laser cut copper up to 3mm thick - above this the laser scurries off into a corner and starts rocking back and forth and sucking its thumb!