This case is very thin, with smooth contours. I was careful to make sure that the openings for the phone buttons and camera were precisely located. The vertical and horizontal curve profiles are very close to apple specs.
I tried other designs from various sites, and was disappointed by poor fit, hole mis-alignment, and unnecessarily sharp edges.
150 um, or 200um
I have built these models with PLA and with PETG. I recommend using 0.2 mm resolution for printing with PETG (for better bridging at the button holes).
Important Note on scaling:
These models are designed to precisely match the iPhone exteriors. Due to normal tolerances in printing, you should consider scaling up the model in your slicer, depending on the type of material you are using.
If using a flexible material, no scaling (100%) is recommended.
For PLA, or PETG, use this scaling:
X -- 100.50% (width, 80.81mm for the 7+, and 69.26mm for the 7)
Y -- 100.30% (length, 160.73mm for the 7+, and 140.11mm for the 7)
Z -- 104.00% (thickness, 8.09mm for the 7+, and 7.87mm for the 7)