Details in the process of making "blacker than vantablack" coatings (part 1?)

Recreating MIT's "blacker than vantablack" in a home shop (almost). MIT press release: http://news.mit.edu/2019/blackest-black-material-cnt-0913 MIT nanotube-on-aluminum paper: https://sci-hub.tw/https://doi.org/10.1021/acsami.9b08290 NIST nanotube darkness comparison: https://aip.scitation.org/doi/pdf/10.1063/1.5009190 Shaper handheld CNC router: https://www.shapertools.com/
Almost-as-large quartz tube (I used 76mm OD) : https://www.ebay.com/itm/Fused-quartz-glass-tubing-OD-50mm-x-ID-46mm-x-L-1-240mm-48-Free-Shipping/113713893883 Insulating firebrick for tube furnace: https://www.ebay.com/itm/Insulating-FireBrick-Thermal-Ceramics-K-26-3-10-pk/131698699891 Black velvet on Amazon: https://www.amazon.com/gp/product/B07BGZ82XH/ LR-1 spectrometer: http://www.aseq-instruments.com/LR1.html Applied Science on Patreon: https://www.patreon.com/AppliedScience