I love this stuff!  I really does cover imperfections perfectly and it goes on super smoothly.  I don't have any tattoos so I took a black permanent marker  and drew a smiley face with thick lines on the back of my hand.  I used only a little bit of Dermablend and it totally hid it.  You can't see it at all.  And I only used a little bit of the Dermablend so this 1 oz. jar should last a long time.  I supposed it depends on where you use this product if reapplication would be necessary.  If you use it on your hands then you will probably need to re-apply after washing them.  I washed my hands and some of the Dermablend came off, especially after toweling them dry.  But that's the only situation I see that re-application would be necessary during the day.  It's a make-up so it's not permanent and you'd want to wash it off eventually anyway.  It will rub off on your clothing too so think about where you're applying it and what you're wearing.