Using UVMapper, I've put together a flat, color-separated version of a body. This is the UV coordinates for a basic body map. It's a 2D map of a 3D body. Usually used to add texture to 3D models, I use it to give me a default shape. I blow it up in Photoshop, print it out on pieces of paper, tape them together, then put it on a light box and sketch out larger pieces.

One page is the upper body, the other is lower. Both print at US legal size, 8.5" x 14".

Here's the arm reference I use to sketch designs over. I lightened the muscle lines and included a space for notes. Thank to Markus, I made sure to keep the wrist in a relaxed position (as opposed to twisted). The result works well.

Three views: rear, direct side, and bicep forward

For some reason, I've always loved this booklet by W.E. Dennis. It's been available online for awhile, but never quite accessible enough for me to utilize. So I spent some time with it: cleaned up the scans, adjusted rotations, resized it to fit on normal paper, and condensed even more to my liking.

Go here for more Rare Books on Calligraphy, Penmanship, and Pen Art. The page has a list of raw, scanned e-books to download for free.

We always make a point to add our own take and spin into the final tattoo design. But this is my starting point for tattoos that are frequently requested. Having been compiled over the last few months, it's ready for use.

Of note: I picked based on quality of image, accuracy when enlarged, and how the image will transfer into a tattoo.