Electroluminescent (EL) Panel - 20cm x 15cm Aqua is a big sheet of flexible plastic coated with EL material so it’s like one big glowing square. It emits an even aqua glow over the entire shape, and you can even cut it into any shape you want using scissors as long as the connector is still attached. Another option if you want to have a custom design, cutting something opaque to 'mask it' or printing onto a transparency and placing that on top. It is not suggested to laser cutting it (the coating may be toxic), although a vinyl-cutter might work OK.
Electroluminescent (EL) Panel - 20cm x 15cm Aqua dimensions are 20 cm x 15 cm (7.9" x 5.9"), about 0.5mm thick. It is covered in what seems to be PVC, the panel is thus spill proof - but note that the connector is NOT waterproof, just a bit of heatshrink. Therefore, leaving outdoors for extended periods is not suggested.
Electroluminescent (EL) Panel - 20cm x 15cm Aqua comes with a matching high power 12V inverter and a female DC jack so you can plug it directly into a 12V supply. The inverter is a 'potted waterproof type' and is thus very quiet. The full panel draws about 210 mA from a 12V supply.
Adafruit Product Page: https://www.adafruit.com/products/414