Addressable LEDs ribbon
Make a display using addressable LEDs, 10-12 m long, 8-10 strands wide. Using LEDs with a 10 cm pitch, make the strands 10 cm apart to give a long narrow matrix effect. Wire connection rather then flex PCB looks better. 12v is better than v; at 10 m there may be too much power drop off with 5v strips.
With a LED spacing of 10 cm, need 100 x 8 = 800 – 1200 LEDs, or in total strand length 80 m – 120 m.
Inexpensive addressable LEDs connected with wire rather than flex PCB:
12V WS2811 WS2812 3PIN Clear Lense LED String Lights Dream Color RGBIC, 2000 LEDs $178.
WS2812B RGBIC Christmas Lights LED String, 50 LEDS 5 meters, $9. Total cost for 1000 LEDs is $215.
BTF-LIGHTING WS2812B IC RGB Pebble Pixel Seed 12V, 66 feet, 200 LEDs, $32. Total cost for 1000 LEDs, $160.
Addressable LEDs guide: Quinled, Hookup Home Auto.