Bill - the July 2021 issue of Kitplanes has an article describing exactly how I do prop comparisons - the test cards are a natural fallout of the procedures.
Paul F. Dye
Editor at Large - KITPLANES Magazine
RV-8 - N188PD
RV-6 (By Marriage) - N164MS - "Mikey"
RV-3B - N13PL - "Tsamsiyu"
A&P, EAA Tech Counselor/Flight Advisor
Dayton Valley Airpark (A34)