SETTING for PLA: Wall Thickness: 0.8 mm – The Extrusion of our printer's nozzle is 0.4 mm. Therefore 1 shell is not enough to provide sufficiant strenght, however 2 shells and a total wall thickness of 0.8 mm gives a good print result. This will be a strong and durable USB case in fact. Infill: 15% – Minimum 15% infill is recommended for stability. Otherwise the outcome might easily brake. Please use this setting for satisfactory result. Obviously you can higher the percentage of infill, but do not lower them for the sake of strength and durability. This is a honeycomb-shaped infill. In case you use this setting of 15% infill one print will take about 30 mins, no more. Printing Speed: 150 mm/sec – Printing Speed has an influence on quality.