The mirrors start out from Schott Supremax 33 borosilicate (precision annealed) blanks. They are places in Strasbaugh grinding/polishing machines. Each machine pictured can hold up to a 28" mirror and another machine that I have (not pictured can hold up to a 32" mirror). Zonal readings are made in a test tunnel. As the mirror approaches completion, alternating Coudé masks with overlapping zonal coverage are used. When the mirror has been figured to the laboratory threshold, it goes outside for star testing. Now the mirror's telescopic figure can be monitored, documented, and adjusted if necessary.   Getting ready to star-test a 24-inch mirror (below). Aluminum telescope and integrated platform built by Tom Osypowski of Equatorial Platforms.   I have an adjustable telescope to star-test and demonstrate mirrors up to 32 inches. You are welcome to come to my shop and inspect your mirror before it is coated.