Mix 2 teaspoons of white vinegar with 1 liter (qt) warm water. Use crumpled newspaper or cotton cloth to clean. Don’t clean windows if the sun is on them, or if they are warm, or streaks will show on drying. The All-Purpose Cleaner (above) also works well on windows. Be sure to follow the recipe, because using too strong a solution of vinegar will etch the glass and eventually cloud it.