Supports or rafts: This part does not need supports or rafts. The last layers of the object have been designed as a bridge and not as a dome. Also, the bridge is inside and therefore there is no point to waste material.
Perimeters: Three lines perimeter.
Layer Height: Low layer height, i.e. 0.1 mm. Otherwise, medium layer and low layer only for the last top layers.
Printing speed: High printing speed, with low to medium gap speed.
Travel speed: High.
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Low-cost PLA with unique colors: