This is a replacement bracket for one of the older Hunter Douglas blinds designs that are no longer available for sale or difficult to source.

Print these on their side with automatic supports turned on. I used ASA because it is both rigid, UV resistant and heat resistant. PETG would be too flexible and possibly cold creep over time and PLA would likely soften and sag when the sun is out. 

After I modeled this clip I found another reproduction on Printables: