In Belgium we have a lot of rolling shutters that are manually controlled (with a ribbon).
The plates that cover the built-in ribbon-spool often don't have a long life (they turn yellow and brittle in the sun). In order to replace them the ribbon has to be removed from either the top spool (rolling shutter side) or the bottom spool (built in to the wall).
I set out to design a cover that was a bit easier to replace ... and that I did ...
The ribbon can be slid in between the slightly opened cut on the side. Afterwards the cover holds the cut closed by design.
Sizes may vary, design files can be provided upon simple request ...
They could even be personalised for each room (a name can be added, a special color can be chosen that fits the room best ...)

Print instructions

designed for 3D print so if you print it flat side down any setting would work without support (I guess).