Homebrew PCBs

Hi all,

I have been making some PCBs of late (just getting rolling with some 
projects as I learn about electronics).  The first few boards I 
etched were on the brown fiberglass type material - worked good but 
can dull a band saw blade in a heart beat.

I purchased some large boards from Kelvin and have been etching / 
drilling these for my most recent series of boards.  This material 
is whitish in color, crumbles when you try to cut it with a sheet 
metal shear (hand snips), however, cuts great on the band saw and 
doesn't seem to dull the blade.  

Having made a slight error on a couple of them, I needed to trim 
down the edge. As this wasn't discovered until the components were 
on, I couldn't just run it through the table saw again.  So I trried 
the snips - didn't work.  Ready to give up, I thought I would run it 
against my belt sander and bingo - this stuff sands just wonderful!  
Much easier to sand than the fiberglass products and stinks much 
less too.

Stefan has told me all about the various materials used for PCBs, 
and now I am wondering why there are so many different materials and 
what the advantages / diss-advantages are of them. 

In my very limitted experiences, I am really liking this white 
material but I suspect it is not the best material to use.

So, if you all don't mind, can we discuss the merits of the various 
materials?

Chris