Set of few matrix displays working directly with neopixel strips (16.6mm spacing so the strip will align perfectly to it = 60 pixels/m and is very easy to modify to fit different spacing). 4x4, 10x5, 14x8 examples. With option to parametricaly generate own. Can be printed with no support, but some gluing might be required. You might want to glue LEDs to the bottom so they will stick firmly and glue the front paper as a panel if you wish. Even with regular paper and transparent filament there is still enough separation between pixels as shown in the photos but probably even better results could be achieved when used with a silver/black filament and with some special paper (not sure with what, but I bet there is room for improvement). What I'm glad about that even with this worst-case scenario it still works enough for me.