The danger in using lines instead of dots would be creating a reflective layer which would reject light from the system.
Within seconds, the mirror's reflective layer had been decimated.
After that a spray of a special reflective layer covers the bumps.
The metal is protected by a film of lacquer normally spin coated directly on the reflective layer.
Gold is used as the reflective layer on some high-end CDs.
At this point the discs are clear and contain all the digital information desired; however they cannot be played because there is no reflective layer.
The planet has a reflective layer but the UHF gets through.
The reflective layer is designed to reflect the maximum amount of solar energy incident upon it, back through the glass substrate.
Despite the use of aluminum in generic mirrors, aluminum is not always used as the reflective layer for a solar mirror.
A protective transparent overcoat may be applied to prevent oxidation of the reflective layer.