Why do day-old latex balloons shrink when touched?

[mamayama]

You know how, after a day or two, your pretty latex balloon shrinks down a bit...and if you touch it, it wrinkles and shrinks even more at the spot it was touched. Why? Inquiring kid wants to know...javascript:smilie(':confused:')

[Padeye]

Wow, good question. Since no one has given an answer I'll suggest some experiments. My off the cuff guess is skin oils doing something with the alredy stretched out latex. Try the touching experiment then try it again after washing all the oil off your hands and see if you get the same result.

[ubermensch]

I'll venture to guess that some of the air has leaked out, and the latex (at one point stretched to capacity) hasn't shrunk to optimal size for the amount of air still inside the balloon.

does that make sense?