Cutting your own copper shapes can be easier than you think.
Cutting copper sheet with a torch.
Elevate and support one edge of sheet with free hand allowing entry point for cut enough clearance for metal cutting sheer to proceed.
For thicker copper sheet you would want to use a jewelry saw it s a bit slower but gives you a nicer finished cutting edge.
Mark the required dimensions on the surface of the sheet using marking tool and straightedge.
The sheers handles are brought together to cut through the sheet.
Cutting slower will also give you plenty of opportunity to blow away the bits and pieces of copper and dust caused by the cutting process.
Begin cut with metal cutting sheer.
Once the copper sheet has been marked where it needs to be cut the sheers blades are positioned on each side of the sheet as would be regular scissors when cutting paper.
Take your time and let the cutter work its way through the copper for a straighter and even cut.
While you can still cut the copper material with the plasma cutter you should not force it and cut too fast.
For higher gauges meaning thinner copper you can easily do it with standard hardware store metal snips.