Fill a large bowl with ice and add water to create an ice bath.
Bring a large pot of water to a boil.
Working in small batches (4-5 tomatoes at a time), add tomatoes to boiling water and boil for 45 second to 1 minute at the most. If your tomatoes are small, 45 seconds should be enough. You aren't trying to cook the tomatoes, only loosening the skin.
Remove tomatoes to ice bath and let cool for 5 minutes before removing and peeling the skin. Most of my tomatoes peeled easily, but for some I had to use (gently) a vegetable peeler.
Cut the tomatoes into quarters lengthwise and remove and tough green parts along with any stems.
Add tomatoes to the dehydrator. I used screens, but you don't need them.
Turn dehydrator to 145 F and dry until the tomatoes are leathery, but not crispy. There should be no visible signs of water and no water should escape when you squeeze the tomatoes. Rotate the trays every hour to ensure consistent drying. Larger pieces may require longer drying times.
Let tomatoes cool before using, or freeze and vacuum pack for later use.