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This REALLY depends on how you are doing things and the razor you are honing
By adding 1 drop of Dish soap in the water you are using it will change the surface tension and some people like it better
Adding a sheet of Plain old Copy paper under the Finishing Film you decide on also changes the dynamic too
I am simply not a huge proponent of Lapping Film BUT it does work and work well if you mess with it a bit, I find it rather unforgiving, which never made sense why so many recommend it to newer honers ???
But to be sure half the solution to it is based on the "Base" that you start with, a nice 4x10 piece of Polished Mable or Granite is the best I have found for it
It is fun to experiment with.
From what I have seen, honing on film is much more of a thing on B&B, where it is recommended a lot as a low-cost entry to honing. Never tried it myself, but it might be Seraphim over there who has it down to a science.