This is a project from France, they will use the rigid PCB board, but these PCB not square, not rectangle, 

but trapezoidal.

They asked use 5630 4000K CCT LED chip, each panel have 7x4=28LEDs, DC24V, 8W.the size is 

10x12.5x18(high)cm, and this PCB board with aluminum materials, 1.5mm thickness,it will be more good 

 for the heat dissipation.