We tested the design rules by using the traces test that Professor Gershenfeld provided.
The first (1/64" inch) end mill we used was well worn so many of the signs of an old end mill were apparent and the quality was not as good. We tried with another much newer one. It is interesting to note the different in quality.
The lines start being stable at around .009 inches.
We submitted our board to a board house, JLCPCB, and received a quote. We were able to get a quote for 5 boards for $4. What a steal!