When I saw this item on Thingiverse, https://www.thingiverse.com/thing:4498623
I immediately thought it looked like a dispenser for rolls of electrical tape. I was wrong, but it took just a few changes to make it a good fit.

While the rolls of Scotch 35 electrical tape fit great, the serrated edge for cutting the tape was mostly a failure. I tried two different designs without any improvement.

You can't just pull on an edge and have it tear like paper. The problem with good electrical tape is it doesn't tear. If you pull it hard enough, it will stretch until it breaks.

While it is easy to see that a serrated plastic edges are not sharp enough. I ran tests using jig saw blades with differs tooth count and tooth shape. None of them worked. Often the teeth would shred the tape into ribbons instead of cutting it across the width.

The design needs some kind of sharp blade, but how to do this safely? An exposed razor blade is not the safest of choices. There are letter openers that use an imbedded razor blade, but I'm not sure this is a good option for electrical tape.

Still I like the basic design. Using it this way at the bench or while doing simple field work will be ok. The end of the tape is held on the tab, making it easy to find. I can then use scissors or a knife to cut it.

Let me know what you think and share ideas for improvement.

BTW, 3M Scotch Super 33+ rolls also should work. They appear to have the same core and outside diameter.