Peel the cucumbers if you like, or for a stripey effect, alternate peeled and unpeeled sections around the width of the cucumber. Cut into very very thin slices and put them in a bowl.
Pour enough seasoned vinegar to come about halfway up the cukes. Stir it around, so that all the slices are coated.
Chill in the refrigerator until ready to serve.
Notes
Ideas for garnishes: toasted sesame seeds; furikake, a seaweed-based seasoning you can get at a Japanese grocery; cooked crab or shrimp; a thin slice of lemon.