The cloths work best dry or slightly damp and will bring out the shine on your coffee equipment and other kitchen appliances. They are really great on stainless steel or on chrome and will not leave any watermarks. Really great for steam wands. Box set contains 2 grey and 2 black cloths; we chose 2 colours so that you can assign a particular task to one colour – in particular differentiating a milk cloth from a regular counter or machine cloth. So the annoying person who leaves milky streaks accross the front of the espresso machine will now have no excuse for doing it again!