Heat oven to 200 degrees.

Set a wire rack in a sheet pan. Cover rack with parchment paper.

Using a mandoline slicer or very sharp knife, slices oranges and other citrus into very thin slices - ⅛ to ¼ inch thick.

Place citrus slices on a paper towel and gently pat dry to remove any excess moisture.

Lay orange slices in a single layer on the parchment cover rack.

Place in the oven and bake for 3 hours, flipping slices every 30-60 minutes.

Once slices are dry to the touch (they should not feel wet or sticky), remove from the oven.

Allow to cool to room temperature before storing in an airtight container or glass jar in a dry, dark place.

Dehydrated orange slices will stay edible for up to 1 year, and look good in decor for much longer than that.