Machine Gun Kelly took to Instagram to share the process behind his massive torso blackout tattoo ... to cover up his old tattoos -- seven intense tattoo sessions over two weeks, bloody arms ...

Daughtry isn't the first celeb to cover up his old ink in such a drastic fashion, as both the aforementioned MGK and Kat Von D have had similar blackout jobs. For more stars with tattoo regrets ...

Machine Gun Kelly is giving fans more insight into his decision to cover much of his fan-favorite chest and arm tattoos with a dramatic — and now viral — blackout tattoo. In his new piano rap ...