the pink/red paper is called rosin paper.

the black tar paper (black #15 felt) is better because it serves as a moisture retarder and somewhat of a barrier. It should be #15 felt per NOFMA specs.

the rosin paper will soak up moisture and deteriorate if moisture becomes and issue or a water leak/penetration into the space.

no it wont bleed through your wood.

people use rosin paper becasue it is dirt cheap.

here is some more information:

Hardwood Flooring Installation:

http://flooringworld.org/floorsearch.php?query=hardwood+flooring+installation

Nail-Down Hardwork Instructions:

http://nofma.org/Portals/0/Publications/Moore%2009_03.pdf

Underlayment and Subfloor Prep for Wood Floors:

http://nofma.org/Portals/0/Publications/Moore%2010_03.pdf

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There are two ways to do any job.

The right way and the wrong way.

Do it right everytime.

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http://flooringworld.org/

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