We applied some Magnetic Developer to a piece of LINCtape and can see the tracks. You can clearly see the extra space between the Mark and Data tracks. When we can get access to a microscope with an attached camera we should be able to see the bits.
This time with a link: https://4310b1a9-a-11c96037-s-sites.googlegroups.com/a/ricomputermuseum.org/home/Home/equipment/dec-pdp-12/dec-pdp-12-restoration-blog-starting-1117/LINCtape.jpg?attachauth=ANoY7crWpMHnAmKM5uJHjnQdBf8OjUGppu7L8jyRjjX7JbwKOEmr3UG5CuJRIjhNfyKg5i8hb28HUOxPNVL5MWOYcznb3A_jQppAFCo0-jugYySIvV0ayvjCgcoMOeb8Z-Zr5Fw4i38VFDaGxDFNVmF1_pBRmcKn5xr_chFmT7ll89yG6tbE4ZYRYQIsAc1kzc1TE9OWpNBxiZ5HiUyPgRF2EClF8Q2IZCErBDwIL8n3comaHcvzzlWKFeC0v3Xl1iaeYHRDgtWb-jdyODHsM7AmxTrDfSmJ2ANEzIC_BYTkJQJ85Fur3rzBRVVxlO9MnZlg8_CUM2lP&attredirects=0 -- Michael Thompson