My husband is getting out of prison soon, now while he has been in there he got some tattoos. How much more difficult isn't going to be to cover up tattoos done in prison rather than the ones done at a shop?

"Jail-house tats" as they are also known can be difficult to cover up, usually they are done with pen ink and something sharp. Which can also lead to ink poisoning. It may cost a little bit more than just getting a tattoo at a tattoo shop but most places are willing to do "cover-up" work for anyone. When you go in, or call the tattoo shop be sure to mention that you are looking to cover up tattoo's. Depending on how long ago the tattoo was done also determines if they can or will cover them. If its been done in the last few weeks they may ask you to wait to ensure that the original tattoo has healed completely thus lowering the chance for scarring.
Also please insure that the tattoo shop you are going to practices safely. With clean instruments, brand new needles, new gloves and is a sterile environment

Not a direct answer to your question but I wanted to alert you that your husband should be tested for HIV and hepatitis and you should not have unprotected sex with him until you have safe results, as transmission of both are risks with prison tatoos. Hepatitis in particular is a particularly high risk for individuals who have served time and tatoos are a key way in which it is transmitted. He probably is fine, but the diseases are sexually transmitted, so I wanted to make sure you know about the risk and can proceed carefully.