I designed these brackets to work with the existing twin slot wall uprights and 220mm brackets (SDB220BC) the brackets sit in the shelving brackets and are the perfect distance to support the filament between two uprights which are horizontal as shelves (Please see picture)

I've put mine at a distance to hold 14x 1kg rolls per shelf (1m), no doubt it could carry more but this is the distance I feel is safe to support my filament.

Print the bracket inserts, check the fit with the twin slot SDB220BC brackets, fit the bracket into the twin slot upright wall mount then screw the 3D print insert into the bracket with 2x 4.0 20mm self tapping screws. There are screws holes on the print so be sure the screw goes into the correct place. I purposely designed the 3D print to stop the twin slot bracket being able to come off without removing the print first.

Anyway I hope this gets used by many as its a very cheap way of storing boxed, vacuum bagged and loose rolls of filament all on the same shelves as you can see in my pictures. Happy Printing!