when i put drops of paint(acrylic)on a piece of glass and lay another
piece of glass on top of the paint and press down lightly the paint
always develops into a strange "vein" pattern. can you explain why and
how this happens,also is there anything occuring naturally in this
pattern? it reminds me of a tree or vein. if you need pictures i can
send them

I have seen similar fractal patterns. These links may interest you:

"Sergio Rica is fascinated with many kinds of patterns, as you
probably have seen elsewhere on this site. He studies theoretical
examples in numerical quantum fields. He also studies experimental
examples in drying paint. His paint was diluted, so that it lacked the
viscous properties that produce a thick, even coat of paint. But it
still have plenty of suspended pigment particles. He let the paint dry
between two panes of glass with a millimeter spacing between them. If
you've ever let buttermilk dry on the sides of a glass, you've seen
the kind of graceful branched structures that result. These patterns
seem to be variants of the lace patterns that U of C student Robert
Deegan saw in his own evaporation experiments. Between the branches,
are draped festoons fine lines. It seems that as the water retracted
in discrete jumps as it evaporated."

http://jfi.uchicago.edu/~tten/Chile/Dec2003.letter.html

A fractal image of paint sandwiched between two panes of glass:
http://jfi.uchicago.edu/~tten/Chile/Sergio's%20site/drying.jpg

A scientist who studies such things:

http://chaos.ph.utexas.edu/~rddeegan/

In millionth of an inch, glass does not have a flat surface so the two
panes actually touch only three places, unless squeezed tightly. My
guess is the patterns are mostly the result of these tiny flatness
errors.  Neil