I just did a Google search (unibind supplies) when I needed extra covers and found a lot of vendors.
I have used this binding approach several times with very good success. There are however several tricks that make using it easier and these tricks are worth communicating. You can give out my email address and have the person contact me directly with any questions.
Thank you so much for your reply Bob. You mentioned there are tricks in using the machine. I'm curious - what are they? I want to be really sure before I purchase this. Thank you so much for all of your help. I really appreciate it!