I have been ordering different flavors to try. I have new tanks and mega cartos, also some cleaned out prefills. I have read postings from folks in various forums about how to keep up with what flavor is in which carto. Many of them print on tiny pieces of paper in very tiny writing and tape them on to the carto.
Well, I didn't want to get into all that, but my memory ain't what it used to be. So.....my granddaughter talked me into buying her a pack of 1800 tiny rubber bands in all kinds of colors. It struck me that they were about the same diameter as the ego batt. I stacked several on my batt and it improved the gripability. Then I took different colors and put one on the top each juice, and the same color on the carto containing that flavor.
Now each juice has it's own color of rubber band so I can keep up with it all.
Works for me.