One of the reasons I like the cutter I recommended is that only one of my two hands is capable of either accurately holding film still or cutting film with scissors

A "guillotine" type cutter solves that problem - my weaker hand is quite capable of handling the blade. A rotary cutter will also work.

The "Dr. T" film cutter adds the translucent base, guides that hold the film straight and distance markers, so it works even better than a plain "guillotine" type cutter, especially with slide film.