It's easy to miss a spot while applying sunscreen, especially aerosols. Color the product so complete coverage is ensured during application, while using a mirror or helper. After a brief exposure to air or sun, the sunscreen would become transparent.

Edit 2010 8 27 Thank you Jutta. My search did not include the work "disappearing" apparently I searched for "~transparent" sunscreen in my Google search. I would like to see the list of the synonyms Google uses when the engine searches for a word with a tildeplaced in front of the word -- not that it would have helped in this case apparently.
-- Sunstone, Aug 20 2010

Color changing materials http://www.google.c...=&aql=&oq=&gs_rfai=
Items that change color when exposed to air or sunlight [Sunstone, Aug 20 2010]

Not exactly the same but proof that the concept could work though. (+) http://www.freepate...ne.com/6361763.html
[2 fries shy of a happy meal, Aug 21 2010]

Avon "Disappearing Color" Sunscreen for kids http://www.epinions...ontent_433162063492
Disappears by rubbing it in, not exposure. Otherwise, yes, it's blue. [jutta, Aug 22 2010]

Avon disappearing sunscreen http://www.google.c...m=3&ved=0CDMQrQQwAg
Avon disappearing sunscreen [Sunstone, Aug 27 2010]

Google search cheatsheet http://websearch.ab...ooglecheatsheet.htm
Google search cheatsheet [Sunstone, Aug 27 2010]

No need; just wait. Later on, the bits you missed will be a distinctive red colour, and quite remarkably painful.
-- 8th of 7, Aug 20 2010


make it blue - smurfs rule, o.k.
-- po, Aug 21 2010


[po]//make it blue// Woad?
-- mouseposture, Aug 21 2010


//It's easy to miss a spot while applying sunscreen, especially aerosols.//

[bad swedish accent] you could get a friend to spray you while you bend over [\bsa]
-- MaxwellBuchanan, Aug 22 2010


aerosol sun screen: because even the most innocent touching is bad.
-- WcW, Aug 27 2010


I honestly thought this was widely known to exist per Jutta's link and others.
-- MechE, Aug 27 2010



random, halfbakery