-- very well organized online catalog, but sometimes more expensive. Extremely fast shipping
(here in California
orders sometimes arrive the same day).
-- often the least expensive for random industrial parts
, fast shipping
, they often have sales with 20-50% off on huge classes
of things ("safety equipment" "metal cutting tools"...), so a very good deal if you hit one of those sales.
I've used the 1" lead lined foam with the aluminum
foil face, both on a boat and when building enclosures for machines. It works very, very well, but is also one of the most expensive options. So I am also interested to hear people's experiences with less expensive materials.