Faking a tattoo on a model

Hi, I was wondering how can I make a real looking tattoo on a girls back. so I have just an ordinary picture with girl showing her butt. No i wanna to make a tattoo above. I tried everything, but it all is like fake?

Someone?

thanks!

Change the layer mode to Overlay. That should get you started. You might also try some other modes like Darken or something.

but inst there any decent tutorial about it?

yes there is:

1 - open your but pic
2 - draw your tattoo
3 - Ctrl+T on the tattoo layer and transform to fit the but in the pic
4 - change tattoo layer blending mode to overlay or multiply

there - you're done

There is a tutorial in "Photoshop Down and Dirty".

Also, you can select the area of the butt you want to put the tattoo on, then create an image map(?) of that (sorry I am not able to open ps right now to give you an exact menu link), then select your tatto, with filters --> displacement map (I believe) you can displace the tatto to the shape of the area on the butt your want. Then use the blending modes (like overlay) to make it look more like its "on the skin".

Use Paavo's fake graffiti tut and see if you can get a tattoo type effect. Heres the link to his site.. http://astudios.org/dark/index.php

Good luck