very impressive methods that you have developed and very useful information for our FOSSIL community. Thanks you for sharing these experience. I would like to add another method that I was using labeling fossils. I was in charge of the paleobotany collection in Leipzig for a long time and to label fine clay sediment blocks was not always easy since little pieces of paper would not last very long even if you cover it with glue. I was using Tipp-Ex, a German liquid correction fluid like White-Out in the states. You just have to clean and smooth the area where you put on the White-Out. It last much longer than the paper since it soaks better into the sediment. Once it has dried you can write on it with a very fine dip pen. You can also use the White-Out as the basement to glue a printed label on the fossil.
I hope that was helpful too.