When I finally got around to trying out another reed tip, I discovered there is more about sand paper than the gritty, coarse type my husband uses in his DIY kit. It was in the Hartmann Reeds website, that I visited to read some reed adjustment tips, where I came across this nugget.
There are different grades of sandpaper, that represent the variation in quality of the abrasive edges, the backing material that support them and the bonding agents that keep everything together. Low numbers like 40 and 60 are very rough and made for heavy jobs, you want to keep these as far as possible from your reeds! There are also super high numbers, like the 3000-grit that is used for buffing and car paint repair, but they don’t do much for the matter in our hands.
I used to try to adjust my reeds with a coarse 150-grit, that would, of course, be too rough for the task and leave the reed in a rather bad shape. The 1000-grit smooths and reduces the Hartmann reeds very neatly, and leaves a much better texture on my lip too. I will make sure to have some at hand from now on!