If your skin is sensitive to sunlight, it would be cool to have a whole-body tattoo of UV-blocking ink that is also invisible to the naked eye. Then you could go out and enjoy yourself and not have to worry about applying sunscreen. I don't think it would be too hard to create the invisible UV-blocking ink, because existing sunblock is transparent to the spectrum of light that humans perceive already.
-- lawpoop, May 09 2007

Nanoparticle Titanium Sunscreen Nanoparticle_20titanium_20sunscreen
same principle [bungston, May 09 2007]

Gene gun http://www.bio.davi...Bio111/genegun.html
might be useful here. [MaxwellBuchanan, May 11 2007]

how long would it take to have a whole body tat?
-- po, May 09 2007


The cool thing about this is that the tattoo would show up as white against tan skin.
-- bungston, May 09 2007


Tattoo ink is traditionally deposited in the dermis, the stable, second skin layer from the outside. (That's why tattoos don't go away, even though we constantly shed skin cells!)

The epidermis, the layer that sunscreen is trying to protect (and whose bottom, or "basal" cells produce melanoma when things go wrong), is the layer *above* the dermis.
-- jutta, May 09 2007


Epidermal melatonin laser diffusion surgery ought to do just fine. However, once you go black, you can never go back unless you wanna be like MJ or something.
-- quantum_flux, May 11 2007


So, rather than either get a natural suntan, or apply suntan lotion, you would rather be stuck with tattooing needles over 100% of your body surface?

Sheesh.
-- DrCurry, May 11 2007


Can you tattoo ballistically? There is a device for transfecting cells, which is basically a compressed-air gun which fires gold microparticles (usually coated with the DNA you want to get in to the cells). The particles are too small to do much damage, but they do get into the cells.

The efficiency may be very low, but perhaps ink-coated particles would be possible.
-- MaxwellBuchanan, May 11 2007


Whenever someone writes "it would be cool", they don't have an idea, they have a wish. Most "invisible" sunscreens that we spread on break down in less than a day, permanent UV blockers that don't break down are usually opaque.[-]
-- baconbrain, May 11 2007



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