Tan lines are the happy reminders of time well spent outside in the sunshine. Most often people get them from the clothes they're wearing and are stuck with whatever swim suit cut or shirt neckline they pulled on that day. But, you deserve more options than that! Your tan lines can be as expressive as you are.

A sun tattoo gives you the power to harness the suns rays to create your own tan lines. Love pretzels? Get a pretzel tattoo! Want to pay homage to an awesome website? Put its cute robot logo on your arm!

Unlike conventional ink tattoos, a sun tattoo is neither permanent nor painful. You don't have much control over color, and fine details are hard to capture, but sun tattoos are less expensive and you only keep them for as long as you keep your tan.

You will need to devote some substantial time to being outside in the sun, so make sure you have some sunscreen and get ready for a vitamin D boost!

Step 1: Design

Use Adobe Illustrator or a similar vector art program to create the design for the tattoo. Like in any other stencil it is important to keep the pieces as connected as possible. I am sure multi-part stencils would work but I have not tried that yet.

In general, the simplest designs work best, so avoiding small detailed design features is advisable. I live traced the Instructables logo and a line art image of a pretzel for my designs but creating designs by hand for this project would be neat as well. I also tried a bike chain design, but the results from that were not as good.

Step 2: Cut

Aside from the sun and your skin all you will need for this project is a laser cutter a scrap piece of cardboard, some painters' tape, and a roll of K-tape.

Start by sticking one end of your K-tape to the cardboard strip with the painters' tape. Make sure you keep the backing on the K-tape. Next roll out a section of K-tape a few inches longer than your design file and tape the other end down with painters' tape.

Place the cardboard backing with the K-tape on it in the laser cutter and align your file in Illustrator with the location of the tape on the cut bed.

Now, adjust your settings for thick paper and hit the 'GO' button.

I cut out a bunch of extra stencils because I knew I wanted a well defined tattoo, and I predicted that I would need more than one day to get nice dark lines. If you just want a faint hint of your design on your skin, consider only cutting enough for two or three days' exposure.

Step 3: Apply the Stencil

The next step is applying the stencil and basking in some glorious rays.

Don't forget that tattoos are just like real estate: they're all about location location location! You'll want to pick a spot that will find the sun easily and not be constantly moving. I put one of my stencils too close to my knee joint while on a bike trip and all the motion proved too much for the K-tape. Scooting it over a few centimeters out of the action made all the difference in its staying power. This is another bonus of the sun tattoo over the ink tattoo--if the first place you put it isn't quite right, move it.

Be careful with the stencil application. K-tape is super sticky and also super stretchy. Too much stretch will distort your design and make it difficult to re-apply a fresh sticker in the exact same place.

Step 4: Get Some Rays

Grab your shades, put on your sunscreen and get outside! My sun tan tattoos were exposed over a 9 day cycling trip with a friend but a few days at the beach would do the trick for sure. The important part here is the fun in the sun.

I do not recommend extended periods of time in the sun without sunscreen. I applied sunscreen every day while riding. Sunscreen will reduce the effectiveness of the stencil but will keep your skin safe. Be careful when applying sunscreen over the stencil. The oil in sunscreen tends to make the adhesive less sticky.

Step 5: Re-Application

If you are happy with your tattoo's location, keep re-applying your K-Tape in the same spot. You can keep the original piece of tape on as long as you like, but I recommend changing it as the piece gets dirty or starts to peel at the edges. After a day or so the stencil will probably start to fall off in sections. But don't worry, you made multiples!

It is trickier to put on a second stencil in the same exact spot as the first so be careful and go slow. Again, be careful about stretching when peeling the tape backing off and sticking the K-Tape on. The better you can preserve the shape of your design, the more consistent and more crisp your tattoo's edges will be.

Continue re-applying until you and your tattoo reach the desired color. Every body's different, so if you're not getting the desired results immediately remember to be patient and let the sun do the work.

Step 6: Bronze Beauty

After a few days in the sun your new tan lines should be well defined. When people notice and compliment you on your sweet new ink, tell them it was done by Titan, god of the sun.