ATM Silvering materials

[BOB PRABOWO <BOB@bahana.co.id>]

Hi guys,

I'm about to purchase some chemical materials to silver my mirror. I
called several chem stores here. But I'm a bit confused.
There are two types of materials (according to the stores clerk), one is
what they call laboratorium grade and the second one is called
industrial grade.
The latter is much cheaper than the former. Now which one should I buy?
Judging from the price (and the explanation from the clerks) the ones
with higher purity is the Lab grade, and of course the price is also
much higher, 3 times as expensive than the lab grade.

Should I buy the lab grade? or can I get away with the cheaper
industrial grade? Disadavantage of using the less pure material? Any
comments, advice, anything? Price is the major concern here:-)

In his book, Tex suggests to use chamois (whatever that is). Can I use a
leather instead of this chamois, or is chamois a leather that has gone
through a special process?
Thanks,
Bob P. Sumitro
Jakarta, Indonesia

Seeing me before him 
the enemy raises his sword
to strike,
but by that time 
I already stand behind him

-Morihei Ueshiba-