This is a shelf mounting plate, which replaced the glue on transparent mount. These glue on plates are working great, but I wanted to cover unused screw holes. Unfortunately the tiles behind have dents, which, due to the unlucky placement, caused air gaps and the shelf started tilting downwards. The second shelf is still up and I added a picture of that, so you have a clue how it original looked.

However. I designed a plate, which now utilizes the screw holes I wanted to cover. Since the screw holes are in the middle I advice to use double sided tape behind the mounting plate, or the bracket will start bending, too. The plate I added has a more spread screw arrangement.

The included FreeCAD source file has a spreadsheet, where you can modify everything.

You need to print the plate and two times the mounting points. This way you don't need any support, which would be hard to be removed.

I strongly advice to use ABS. Not because of the flex, but because you are able to weld the mounting points with a little acetone to the bracket. The bond is even stronger than any layer line. With other materials make sure your glue is doing its job. You can see the slightly smudged backside, where the ABS got melted. The quality does not matter as you cannot see the entire bracket once the shelf is slit on.