Do I have to go to an ink fingerprinting agency or can I do it myself?

I need to get an FBI check for applying for some jobs.

When I went to a fingerprinting agency to do the ink fingerprints, it cost $20 per ink card when I went. Since I need to get 3 or 4 of them done, is it possible to just do it myself. I bought the ink cards and the ink, and I know how to do it correctly, since I've done it at the fingerprinting places more than once, but after looking at it, there is a space where an official fingerprinting agent is supposed to sign it.

So is it required that I go somewhere, or is it just recommended? It's going to cost me $60-$80 just to get 3 or 4 of them done, so it will get expensive.

Thanks.