Here is my version of a glass sliding door handle. It has 1cm space for the glass in between the handles. It has enough grip to slide the door, couldn't make more grip because the door should slide next to other glass doors. I attached it with some adhesive to the glass, which is again easy to remove, in case I want something else. Advise is to print it with ASA or with filament with carbon in it. It should be stiff and strong. Didn't try PLA myself..