I just recently went to ComiCon and Dressed up as a Slytherine Student. I needed a way to make a DarkMark that would wash off later so I didn't get in trouble at school .
Step 1: Materials
The Materials you need should be very easy to find.
Step 2: First Things First
Now what you need to do is find a picture from the internet that you want to use as your "tattoo". You'll probably want an image that is black and white and has little to no detail.
Step 3: Print
Now you must transfer your image from the digital world to the real world. PRINT IT.
Step 4: Cut
Cut out around your picture.
Step 5: Tape
Now take three pieces of tape, close to the same size of your picture, and put them on both sides and the top of your picture. and tape it to your body where you want the "tattoo".
Step 6: Trace
Now take your sharpie and trace the outline of your picture
Step 7: Color and Detail
Now that you have the basic outline on your body darken it and add all the details you want.
Step 8: Finish
Now go out and rock your "tattoo"