suction cups and regular window hooks should not be used to hang the frames on this site. The frames are much too heavy for that.
As a solution, I tested a few hooks and found this one to be incredibly strong if used correctly.
You must press the center first, and push out any air pockets.
I bought this on that very popular website that everyone orders everything from but I don’t want to mention here in case google analytics penalizes for that sort of thing.
anyway, they come in packs of 8 for $10, so you can buy a single here if you’d like or a pack from them. Another option is to put a nail in the frame of your window. My windows are some sort of non-wood material so that wasn’t an option for me.
I cannot accept returns if you use this incorrectly or don’t use a strong enough nail, so please use extra care when hanging your art.