ok thanks, I will
meanwhile I discovered you can do that also by selecting the entire album (as opposed to selecting the songs independently) and click show info. It ask whether you want to edit for multiple files, click yes, and past the albumart. can be anything really. Since it s so easy to find the right albumart on the internet, it's rather remarkable Itunes often does not find the right pic to go with the albums.
Had different problems with that on XLD, Max, so apparently no universal method found yet.
It doesn't matter, either way will work. But remember WAV files do not support metadata, so tags or artwork for WAV files are always stored in the iTunes database and will not be seen outside of iTunes. For that reason, WAV is not a good format to choose for your library.
Steve