Designed these to hook over the back of our kitchen and dining room chairs to hold a cane. Sturdy enough for more, just don't want to load too much and tip the chair. I've included the two sizes + templates you can use to check/adjust the fit for your chairs.
The small chair hook is 19mm and the large is 35mm where they hook over the chair. Print the templates and play with the scale on your printer until you get a fit that works for you.
I printed these with PETG and 3 perimeter walls and 25% gyroid infill for strength.
I have a different version that fits over the top of a Windsor style chair https://www.printables.com/model/843683-2-piece-chair-back-cane-hook It is two piece and locks onto the top via a dovetail joint, no glue or fasteners.
The author marked this model as their own original creation.