Use any properly rated wire of the appropriate gauge thickness to create connections and extensions between sections of LED lighting, power supplies, RGB controllers and dimmers. Shorter and/or thicker wires will always mean less voltage drop and better LED brightness. For example, if you are using white LEDs (60 LEDs/meter) and the tape length is 12 ft., the maximum wire length from the LED tape to the power supply should be no more than 10 ft. using 22 AWG or 20 ft. if using thicker 18 AWG.
Select from flat ribbon or round:
Flat ribbon is for use outside of walls only, very low profile
Round is safety rated for use inside of walls, with PVC jacket