Most people prefer smoother paper but it’s up to personal preference.
If you are getting paper not necessarily made for use with fountain pens denser tends to be better but paper actually made for fountain pens tends to deal with all the weird issues with ink absorbance with coatings or the material blend of the paper. As a rule of thumb though the finer and dryer your nib and feed write the less you have to care about all that stuff with absorbance of paper.
I’m all in on that cleeeean coaaal.