The shingles have an uncovered tar band on the top surface where the bottom
of the tabs on the shingle above will rest when installed. This then bonds
the tabs to the shingle below.
On the bottom of the shingle is the strip of cellophane which lies on top of
the tar strip of the shingle below when the shingles are packaged. This
keeps them from sticking together when they are in the packaging. Of course,
if it gets too hot they do stick and you have to cool them off to get them
unstuck without damage.
Billh

"Owen Davies" wrote in message
...
George wrote:

Absolutely. The strip is there to keep them from adhering to each other
in
the package. The reveal used on installation should put the fresh tar
off
of the strip.

Sorry, but I don't quite understand that. I have been doing an excess of
shingle replacement in the wake of the Florida hurricanes, and those
strips are still on all the old shingles. There is no sign that any of
the shingles have adhered to the one underneath, as it seems they would
have done if the (paper, in this case) strips had been removed. And if
that is not the purpose of that band of tar, I can't think what it would
be.

FWIW, in my ignorance I have been pulling the cellophane strip off the tar
and expect the shingles to survive the next hurricane a lot better as a
result.

Owen Davies