Years ago I learned how important reed gaps are. I started setting gaps and soon became addicted. Now it bugs me if just one reed is even slightly off. I learned to use a thin feeler gauge to lift a reed and a long pointy poker to depress a reed...
A few things happened lately that caused me to re-examine the subject of reed gaps.
One, was showing a newer player my method of testing and adjusting gaps. I realized that testing wasn't as tricky as controlling the tools to make the fine adjustments. Even though reeds are not super fragile the work is pretty delicate.
I've also seen experienced harpsmiths have some trouble applying just the right amount of lift or poke to raise or lower a gap, myself included. It often becomes a dance of over doing it and under doing it.
So I started designing what I believe to be the right tool for the job. Here's a video of the tool and a method of assessing and setting reed gaps.
It's an ABS blend similar to what is used for guitar picks. The wedge is made up of 30 welded layers of the ABS blend. It's pretty tough stuff with a bit of flexibility (will not chip). I think it will service hundreds of reeds under typical use, years. If the leading edge ever becomes damaged the wedge can be resharpened using a file.