Bellows are the most overlooked part on a Deardorff Camera.
I make or have bellows made that are exact duplicates of the original factory bellows. They are constructed of three layers. The inner fabric is a proprietary
fabric that was jointly developed by myself and a fabric coater. It is not an off the shelf item. It was chosen to withstand heat and cold and ease of cleaning.
The ribs are standard railroad board. This is a material similar to a file folder except it has a bit of resin in it to make it stiffer than cardboard. The outer fabric is again a proprietary material.  It is a either Nylon or Rayon fabric that is triple coated to resist pinholing. The folds are either a cut corner or an English fold.
Special bellows, wide angle or extra length are available.
As of 1998 I can supply Leather bellows at additional cost.
My bellows are not inexpensive. There is a lot of time and energy used in the creation of these fine bellows. They are a true work or art.
My standard warranty on bellows is 5 Years prorated from date of delivery.
Some size bellows carry a 10 year warranty.
Special bellows carry a 3 year warranty.

As usual, care of the bellows is important. My bellows can be cleaned with a damp sponge and Windex. After it is dry, spray the outer bellows with Spray Lemon Pledge furniture polish. Let it dry a while and wipe off excess. Support the inner surface with your other hand while you wipe off the Pledge.
The inner liner can be wiped down with a damp sponge. Do not Pledge the inside.