This is my version of a shower shelf that doesn't require drilling as it attaches directly to the shower rod. It's heavily inspired by this design: https://www.printables.com/model/558386-shower-basketshelf-easy-print-no-supports

I redesigned it to fit my shower, which I bought on Amazon, that has a rectangular rod: https://www.amazon.it/dp/B00VUS6GS6?ref_=ppx_hzsearch_conn_dt_b_fed_asin_title_5&th=1.

I used a marble effect filament (TINMORRY PETG-Marble-MagicBlue). With a 30% infill, it uses 396g of filament for each print (two pieces, right and left). It's very sturdy, and after a month, it has not shown any signs of failing or degrading from chemical products.

For fastening, I used 4 DIN912 M5x35 screws with 4 M5 nuts embedded in the right shelf. I suggest using galvanized screws to prevent rust.

Here is a timelapse of the printing and assembly: timelapse SHOWER BASKET