Most tattoos out there are purely aesthetic. They’re art for the sake of art, adorning the body. I’m aware of a few more utilitarian tattoos out there in the world. Adam Savage (of Mythbusters) has a ruler tattooed on his arm (inches and centimeters). Someone else has a protractor (degrees and radians). Some people have medical information tattooed (diabetic, list of allergens, do not resuscitate). I’ve seen a periodic table. I know someone who has a simple connect-the-dots shape that they fill in throughout the day to remember to take meds (and to not double-dose or skip a dose).
I don’t think I’m dedicated enough to any of these concepts for a tattoo. Nor am I confident that my skin won’t stretch over time, making measuring illustrations less useful. I use TODO checklists a lot and figured I’d try my hand at designing a rubber stamp. It would allow me to either play with a temporary tattoo or turn a blank index card into a fancy-formatted checklist.
I’m not a stranger to making custom rubber stamps. You may recall my post about Cottage Stationary, in which I made a stamp as the header graphic for hand-made notepads. By comparison, some checkboxes and lines would be a piece of cake.
The one snag is that human arm is a lot more soft and fleshy than paper. Rubber stamps work pretty well on the tight skin on the back of your hand. You can see that at any bar or club that stamps your hand at the door. Your arm though? The kind of depth you get from a rubber stamp just turns your arm into an inky mess. I ended up making a second design — entirely 3D printed — with really deep channels. This one works better when stamping skin.
The rubber stamp works well on paper. The entirely-plastic stamp works well on skin (and not too bad on paper, if you do it right).
After spending time designing and manufacturing the two different stamp variants, the project was successful. With a big asterisk caveat. “Technically successful.” As I mentioned, the rubber stamp works well on paper, but I find it easier to just write a list on paper without using a stamped template. The plastic stamp works well for stamping the fleshy part of your arm —- but when it comes to writing text on the list, I ran into the same kinds of problems as the rubber stamp on that part of the arm. It’s easy to write your phone number on the back of someone’s hand or their palm. It’s much less easy to write legible text on the fleshy part of your own arm, even with a good felt-tipped pen. In the long run I probably won’t use either of these stamps. A checklist tattoo is definitely not in my future.
If you’d like to make these stamps, to see if they work better for you — or if you’d like try remixing your own improvements to my designs — you can find all the files on Thingiverse: Checklist Stamp.