Wash the cukes, leaving the skin on. Using a mandoline, slice into thin coins. If you don't have a mandoline, slice with a sharp knife 1/8" thin, or thinner.
Place the sliced cucumbers in a medium sized bowl (non-metallic), and mix with salt. Set another bowl on top of the cucumbers and place a heavy weight in the top bowl. This allows the cucumbers to release their water.
Place in the refrigerator. Allow to chill for an hour or more, then remove and drain the water from the cukes.
For the dressing, whisk together the vinegars and sugar until the sugar dissolves. Stir in the parsley, chives and pepper.
Pour the dressing over the cucumbers and mix until all of the cuke slices have been coated in the dressing. Return to the refrigerator until ready to serve.