Okay, so Ive looked at just about every tutorial there is and i still dont get it. Excuse me for my stupidity, but I'm hoping some of you can help.
I'm using TSR workshop and I would like to make a chest piece tattoo, along with sleeves and a back piece. What mesh do I use for that? I know some of you said you used the gloves and socks, but when i export them from the Multiplier all I see are just the gloves, or just the feet. How do i get a full body mesh?

Which leads me to my next question, I know this might sound silly to some but i decided to export the Skin Specular and apply my tattoos to that and put it in the multiplier. ofcourse when i loaded it into my game, my sims body was completely black and just the tattoo showed.

What am i doing wrong? I have looked at every tutorial on modthesims and TSR including the basics of retexturing. Can anyone please help?

You do not need a mesh, only a few texture files.
You can use the socks and gloves to do this exept both CTU and TSRW can not preview these.
So you best do your work in Milkshape and then build a package to test ingame....

Edit,
By that i mean:
Export the nude top and bottom mesh and import them in Milkshape.
Apply your tattoo texture as material on the body.
-select all faces
-material tab
-new
-none
browse to your file and import
-assigne
-right click in 3d view and choose textured.

Edit and import till your satisfied, then build a package and load the texture in it.

how do i import it into milkshape? only lets me import a certain file.

okay so without going through milkshape i was able to get the tattoo to show properly in my game. the only problem is the tattoo is way too bright. how do i fix this? thank you for your help thus far!

Edit: what it looks like in CAS

Wat texture did you edit?
If you have edited the multiplier in color you get too bright stuff ingame

what color should my multiplier be? should i keep it blank?
thank you so much for helping, this has been boggling my mind. ive been looking around for hours.

The multiplier should be grey, fairly neutral - 128,128,128 is a good place to start, though it's not exactly right, I always forget the exact values.

Then on the mask, you can paint the areas which will be different colours; use red, green and blue (and alpha if necessary - for that, see the Creating a new RGB mask tutorial in the tutorials section). So, for example using the areas I can see in your picture, you would want to paint the red areas red, the yellow areas green, and the purple areas blue. You can use translucent colours to blend areas, for example to make orange by blending the red area and the green area.
Once you've done that, in either CTU or TSRW (or in CAS), you can set the colour for each channel (red paint = channel 1, blue paint = channel 2, green paint = channel 3, alpha paint = channel 4; so you would set channel 1 to red, channel 2 to yellow, and channel 3 to purple). You can also then play around in CAS to try out extra colour combinations.
If all that is gibberish to you, I suggest the tutorial I mentioned above, it explains masks much more clearly than I do. The tutorial uses clothes, but it's exactly the same for accessories including tattoos.

If you need more colours, for example black outlines, draw these in colour (well, not if it's black outlines, but you understand, I hope...) onto the overlay texture.

And, as an aside, CTU does display gloves and socks properly if you download my fix for it, though I've forgotten where I posted it, it was years ago...

thanks for responding! im guessing all those colors would be if i want to make it colorable? (i dont want it recolorable, sorry should have mentioned that earlier) I just want them to show up like the actual photo. I'll tell you what i did.
I used the body texture as my guide to see where the tattoo needs to be placed, and then i took the body texture away, and deleted it. then applied it as my overlay and multiplier and eventhough it did show up, it came up as that really bright color you see.
im guessing i did something wrong.

only apply it as overlay then, the DDS texture compression format should be DXT5withinterpolatedalpha.
Did you clone socks or gloves, gloves might have a bright specular texture.(check that)

Why wouldn't you want it recolourable? Recolourability makes it more versatile and usable on more different sims.

If you're doing the texture solely on the overlay, you can leave the multiplier blank (grey).

@whiterider: Your fix was posted here http://www.modthesims.info/showthread.php?t=417727 :]

I'm trying to do this too, everything was working but the gloves still show up and I cant get them not to >.<
but all the tats show up in CTU [with gloves] but when i put it in the game, just the gloves show up with the hand tats on them. Its annoying as hell.

Nevermind, I got it work perfectly :D