A simple, fast to print test of salmon skin effect that some printers with cheap low quality stepper drivers suffer from. I used it to evaluate the effect of TL Smoothers I installed on my Ender 3 (with board rev. 1.1.3).

It consists of two test shapes - a plane rotated by 5° in Z and Y axis (where salmon skin is visible as stripes) and a flat elipsoid shape (where it shows as cocentric circles).
On the right side of the photo, the test was printed without the smoothers, on the left, with the smoothers on X and Y. As you can see they worked great, the Salmon Skin almost completely dissapeared.

In the default orientation, it tests the X axis - rotate 90° if you want to test Y, or add another piece to the print rotated if you want both at once.