Synopsis: Learn how ordinary blue painter’s tape can help you cut tight-fitting dovetails every time. Michael Pekovich’s method has been tested on novice woodworkers and it works remarkably well. Just lay a strip of blue tape across the end grain and scribe the joint. Peel away the waste areas, and use the tape as a guide for sawing and paring. Not only does it make layout lines easier to see, but it also serves as a guide for your saw and chisel, ensuring accurate dovetails.

A while back, I was making a tea box out of wenge, which is almost as black as ebony. Chalk it up to old eyes, but for the life of me, I couldn’t see my knife lines. I tried a brighter light and stronger reading glasses, but they didn’t help. Finally, I laid a strip of blue tape across the end grain and re-scribed the joint. Peeling the tape away from the waste areas showed me exactly where I needed to cut. Problem solved.

Not long after that, I was building a dovetailed case in white oak. When it was time to scribe the dovetails I remembered the tape trick and used it again. The first joint I cut fit almost perfectly right off the saw. I attributed it to luck until it happened at the next corner, too. I began to wonder if the blue tape provided more than just a visual guide when sawing.

After a few more dovetails that fit straight from the saw, I had my answer: The tape is just thick enough to act as a shallow fence to register the saw for starting the cut. Sawing to a scribe line alone, the saw can skate across the end grain and away from the scribe line,…