In article .com,
wrote:

What is the trick (s) for spotting RC paper?

PATIENCE :-)

A (000) sable hair brush, Spotone or other retouch
dye the color of the particular color B&W print you have.

A clean cup of water, and dish to dilute the dye,
a good ole paper towel to absorb extra dye from the brush.

Good but not too bright light to work in. Under work the area and build
up to the final density to match the density you desire.

Making a few extra prints of the same shot in case you flub one to the
point the dye won't wash back out completely.

Remembering NOT to try and rewash and fix the final art.

--
LF Website @ http://members.verizon.net/~gregoryblank

"To announce that there must be no criticism of the President,
or that we are to stand by the President, right or wrong,
is not only unpatriotic and servile, but is morally treasonable
to the American public."--Theodore Roosevelt, May 7, 1918