Testing Tool Sharpness Before Making That Cut

I was just about to make a fine detail cut with a tool I have not used in a while. I had second thoughts. What if this tool is not perfectly sharp? The cut will be cross grain and a dull tool would tear the wood fibers requiring me to re-carve the entire surrounding area. The point is, be sure you have a scrap piece of wood you can test your tools on first.

It turns out that the tool was sharp, but I'm still glad I checked first. Do you ever test your tools before making a cut?