The rounded shape keep your hats in the natural shape of your head. When using hooks it will deform your hat, stretching them out. Printing the holders don't take long, approximately 3 hours. I used 10% infill but you could get away with less. print the holders on the wall mounting face to get best results. when mounting use good quality double sided mounting tape. hats can vary in weight and might fall if not a big enough piece or if its poor quality. (WARNING!!) If you don't do properly there s a chance the holders could fall tearing paint and drywall. (ALTHOUGH!!) If done right you wont need to worry about that, and you wont have screw holes in your walls.