..if you're looking at your variator...in the direction that you're installing the rollers, if a roller has more material on one "side", then the heavy material side should be to the left side of the roller, if the roller is being placed in the "top" roller ramp......
..get it?..
..some rollers, and sliders do not have that extra material, and are equal, like the Malossi rollers...in this case i always put the printed side of the roller to the right, so that the writing remains on the roller longer...