A PET bottle organizer/dispenser for Ikea Kallax.
I tested with 500ml bottles and it could hold 6 bottles in total with no sagging (3KG total) without using any glue.
Print settings: 2 walls, 15% grid infill. Printed standing:
If you need it to be stronger, put a drop of superglue after assembling so the two frames won't move. 3 walls may also help for heavier bottles.
STEP file included.