Hi, all.  I have a recipe for 65% hydration and want to know if, in order to keep the percentage, do I need to reserve some of the flour for the board?  Or do I put it all in and use extra flour for the board?  If I do this, does it skew the percentage?  What do you all do?  I heard somewhere that extra flour for working with the dough, etc. doesn't become part of the actual dough, but don't know if it is true...

Susan