What is wall thickness and wall line count?

 wall thickness of two or three times the line width is sufficient. A higher value will create a sturdier model and decreases the chance of leaks, while a lower value can significantly decrease the print time and filament costs.

the above picture shows infill percentages of 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0%infill 100 to 0 shell lines 4
slide to find the difference between 2 layer shell wall and 4 layer shell wall.

Instead of setting a thickness in millimeters, you can also set a number of walls. When you set the wall line count, the wall thickness is calculated and will grey out.

the above picture shows infill percentages of 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0%infill 100 to 0 shell lines 8
slide to find the difference between 2 layer shell wall and 8 layer shell wall.