I’ve been trying to get better at freehand cutting when I make my own stencils, but I keep ending up with these jagged edges or corners that tear. My craft knife is sharp, so I don’t think it’s that. Maybe it’s the material I’m using? I just feel like I’m missing some basic trick everyone else knows.
I hear you the jagged edges in freehand cutting can feel like a wall you keep hitting even when the blade seems sharp.
Try focusing on the blade angle and the direction you pull the cut, keep a light steady pressure and go slowly with several passes.
Sometimes the issue is the stencil material not the knife a stiff Mylar or vinyl can tear or snag and you might need a softer backing.
If the surface catches you end up chasing the line maybe try a smoother cutting mat and a backing that lets the blade slide a bit rather than bite.
A guiding edge can help get a clean start try tracing a line with a ruler or a straight edge then freehand cut small bites.
Some folks swear by a newer blade and a different tempo yet I wonder if it is really the motion more than the tool.
Would a little practice sheet for tracing shapes reveal where the edge starts to fail and give you ideas to adjust?