Another ex-double bassist, but started on Violin for about 10 years. I agree with the above but also add that any permanent markings would be problematic becau

Another ex-double bassist, but started on Violin for about 10 years. I agree with the above but also add that any permanent markings would be problematic because wood expands and shrinks and therefore markings would not remain in the place. That being said, on the rare occasion of a double bass solo in orchestra I would usually mark a starting point on my fingerboard with pencil.