Save money on extension cords by switching to SPT wire! You'll need one extension cord per element connected to an AC controller (like a CTB16PC or LOR1600). SPT wire should NOT be used as pixel extensions, or to provide power to your controllers.
To create your own wires, purchase a spool of SPT 1 or SPT 2 wire, make and female plugs, cut the custom length of wire you need, and snap the plugs on to the respective ends. You MUST use the same SPT 1 or SPT 2 plugs as the wire you purchased - they are not interchangable.
SPT 2 wire has thicker insulation that SPT 1 wire, but this does not change the maximum amount of power that the SPT wire can handle. The maximum amperages for both wires are 10 amps from 0-50 feet, 7 amps from 51-150 feet, and 5 amps for any length beyond 150 feet.
SPT 1 wire can withstand most weather conditions. If you are located in extremely cold or hot climates (like Alaska or near the equator), you should consider SPT 2. Another reason to use SPT 2 wire is for outdoor installations lasting more than 90 days (generally permanent installs). If you do not meet any of these conditions, you are likely okay to use SPT 1 wire and plugs.