After my recent article on shelf liners, I mentioned that you cut cut them with a hobby knife, scissor, or a roller cutter.

Above, you can see a roller cutter I bought at Dollar Tree for $1.25 USD. These are generally used for cutting fabric.

There's a sharp round blade at one end, with a white plastic guard that is shown above in the safety position.

And above, the guard has been retracted and the cutter is ready to cut.

Note that, due to the design of the guard, a roller cutter works best in a vertical position. If you tilt it, the guard starts to get in the way.

Above, I've used the roller cutter to cut out some shelf liner, then used a roll of tape as a guide to rounding the corners. I found it easier to follow a straightedge or curve when the bolt-side was on the outside.

Above, you can see two area cloths I've cut out using the roller cutter.
Is it worth using? Frankly, a hobby knife does everything just as well when cutting shelf liners, and I found it hard to get the roller cutter to follow a curve. Perhaps the roller cutter works better on actual fabric. But it's fun to try a new tool.