This is a simple test for your manual or auto bed leveling. How to use it:

1. Level your bed with the screws. I'd advice you to find a level as low as possible as the springs are stiffer when compressed and the bed is not loosing the level as easily. Adjust your Z end stop height if necessary
2. Perform manual mesh bed leveling as usual
3. Print this test. You can adopt the size to match your printer
4. Use the menu item "Edit Mesh" to adjust the corrections from your manual mesh bed leveling process. Select the X and Y position of the measurement point as shown in the screenshot and adjust the height in e.g. 0.025mm steps until your result is perfect.

This video does an excellent job in explaining how the test rectangles should look like:

Make also sure to tune your extruder E-steps and flow before using this test. The result might be influenced by your printer under or over extruding:

Category: 3D Printing Tests