Basic Scratchbuilding question

The technique for straight lines is called scribing. Place a steel straight-edge along the line and run a No. 11 blade along the edge, lightly at first, then with more pressure. For thick pieces, after the first few cuts, use the back side of the blade. When you are half way through the thickness, bend the part sharply along the cut and it will snap. A few passes with a file cleans up and squares the edges.

Hey Ross,

That's great! Thanks so much for the answer. I never considered that the plastic might snap off. Thanks for taking the time to answer such a basic question.  Now, I'll have to go try it. 

Note that this works well with styrene. It does NOT work well with some acrylics or any polycarbonate!

And you're welcome!