I designed a Suction Cup Clip for mounting papers or as a hanging hook on the glass wall, to keep the wall clean without tape or glue.
The structure is from the clip I designed before, which could keep tightly biting without metal springs.
You can also download the clip free at:
https://makerworld.com/en/models/12900
You can buy the suction cup with M4 thread screw on Amazon, just search"suction cup M4":
https://www.amazon.com/s?k=Suction+M4&ref=nb_sb_noss
Enjoy!
I tried several different structures to make it use well.