Steam tomatoes or dip them in boiling water to loosen skins. Dip in cold water then peel. Cut into sections about 3/4 of an inch wide or slice them. Cut small pear or plum tomatoes in half. Blanch in steam for 3 minutes or in water for 1 minute. Dry in a dehydrator 5 to 8 hours or 6 to 12 hours in an oven.