I would have to agree with Ralph at least pertaining to myself up until several years ago when I finally learned how to put it all together. But with regard to printing and becoming satisfied with my filtration I was using, It wasn't until I learned to determine the relative ISO range number with a given filtration setting on my LPL with my paper developer and toner that I really could appreciate the actual filtration setting being used and how it related to my negatives. I learned how to determine it here, it's a visual method, but a very good one IMO, would love to do it with a reflection densitometer and the paper curve, but it certainly is not necessary. Bottom line is that a #2 filter, for example, may not at all provide a grade 2 contrast, my attachment shows the contrast grades I can reasonably expect with my LPL settings after a single darkroom session of 30 minutes or less. I only mention this because understanding the actual contrast grade one is getting given paper, paper developer, enlarger light source, and toner is hugely beneficial to understanding your own negative development, IMO.