3D Systems Cube User Manual page 9

Purging is not always required but is recommended after performing a long print.
This will ensure that both jets are clear and ready for the next print. Purge the PLA
print jet and then purge the INF print jet before printing a new part.
Position The Part To Optimize The Print
For best results, position PLA parts in a way where there are fewer horizontal spans
between vertical features.
Preferred
Note the horizontal features of this part. Even though the bars in this part span a
significant distance, these features will be properly supported by INF material.
Not Preferred
Note the vertical features of the part in this illustration. Spanning PLA material
between multiple vertical features may not print as intended.
Maintain Larger Footprints
Arrange the part where you will have the largest footprint touching the print pad.