@JWneural @pikuma In this case, it’s more like the orientation of the coordinate system. In a lot of software which deals with 3D objects, the X axis is represented as red, Y is represented as green, and Z is represented as blue (sometimes green and blue are swapped). To help users track orientation, there’s often a point with colored arrows pointing along each axis in the positive direction.

That orientation point-and-arrows looks like the hand in the photo. You might need to paint the right hand to get the axes to come out how you prefer, though, since there are lots of different ways to arrange the axes.

Traditionally, X is horizontal and Y is vertical, making Z depth, but which direction is positive, into the screen or out of it?

3D printers typically work with an X-Y build plate (making them the horizontal axes) and a Z height axis. Some (FDM, SLS) build from the bottom up, while others (STL) build from the top down, so which direction is positive?

These axis orientation combinations are sometimes called chiralities, because you have to mirror coordinates to convert between them.