My lack shelves kept drooping due to "excessive" weight, so I designed these sturdy brackets to keep the shelves square.

It has 10mm wide holes for the base of the screw and 4mm hole for the screws head.

I don't use the lack shelf stock mounts with these. These do require you to drill a screw into the shelf itself.

!!! Caution !!! This will eat a ton of filament. I could make only 2 of these from a 1kg spool of filament with my print settings.