Like Minerva, we have a lot of napkins (I never counted, but there must be at least 40/50 or so). It never even occured to me to use the same one all day or until it was "crusty". I use them at the end of the meals to wipe things up with, so there is pretty much never a clean napkin left. maybe we are just messier than other families

They go in the washer after they are used... so at least 4/8 get washed with each load of dark laundry. They dry so fast, even if the dryer is broken (like it is now) and it is freezing out (like it is now), they dry in no time.
I don't have any that are seasonal, so that is never an issue.