We should not sand fibers in the dark box because depositing dust there could alter results. I have to hold the fiber outside the dark box, sand it, then wipe it with a lint-free cloth before putting it through a chimney. | We should not sand fibers in the dark box because depositing dust there could alter results. I have to hold the fiber outside the dark box, sand it, then wipe it with a lint-free cloth before putting it through a chimney. |