Yes it is.

Some different paper manufacturers use different filters
some have varying color because each manufacturer
makes paper that is somewhat different in it sensitivity
to white light.

Thats incorrect, grade 2 to is typically the standard default
for sensitometry as opposed to 3.

If your using standard methods of testing probably not.

Polycontrast IV is a new product. Using no filter is like a 1 1/2 filter, not #3.

There used to be several versions of Polycontrast, including
Polycontrast Rapid, which was a faster version.

duPont made Varigam, High Speed Varigam, and Varilour. Ilford makes
several varieties too.

The unfiltered paper is close to grade 1 1/2 with most VC papers.

 IV is the latest version of that Kodak VC, variable
contrast, paper. Of course it has Improved Everything. In the
late 50s I was using that paper, likely the totaly
unimproved I.
 For enlarging purposses that's all Kodak produces these
days; RC/VC papers.                                       Dan

Jed -

There are a variety of polycontrast papers on the market, and there are a
number of others that have been formally withdrawn but that may still be
available in dealers.   The basic idea of polycontrast paper is that they
enable the printer to adjust contrast by changing printing filters.

A bit of practical advice - if you are new to printing, don't let
yourself get wound up in discussions of paper grade designations.  In
fact, there are differences in response between different brands of
paper, between variations and types within individual brands, and between
different brands of filters.  The differences are confusing and provide
lots of opportunity for debate in these newsgroups, but beyond that they
are not important.

My first suggestion is to buy a box of paper and a package of filters, go
into your darkroom, and start printing.  Take one negative, and make a
workprint with each filter in the pack.  Process them and dry them, and
then study the results that you get.  You will learn a lot about variable
contrast filtration that way.

You only need one benchmark, and that relates to exposure.  Because
filters absorb some light, they require longer exposure (or a larger
aperture) than printing without a filter.  The best way to calibrate that
filtration is to make a test print.  Set up your enlarge to make whatever
size print is convenient for you, and then use a card to cast a shadow
over most of the print, exposing a narrow band about 1" wide.  Move the
card to make the band 1" wide and repeat the exposure with everything
else unchanged.  Repeat this process until you have finally exposed the
entire sheet.  Process the print, and then pick the band that you think
is dark enough (be sure to evaluate the test print with the lights ON -
you can't judge print quality by safelight).  That then becomes your
standard exposure for all of your test prints.

Start with the #00 filter - that will produce the lowest contrast.  Step
through all your filters, making a print with each one using the same
exposure time and aperture.  When you get to the #3.5 filter, double the
exposure time and continue through the #5 filter.

What these processed, washed and dried prints will teach you is
- contrast increases as the filter number increases
- contrast roughly equates with "grayness"
- modern filters and paper are designed to have the same sensitivity to
light for all filters between #00 and #3, and exactly half that
sensitivity (requiring twice the exposure) for filters #3.5 through #5
- the term "normal" is meaningless - there is no such thing as a
"normal" filter or "normal contrast".  The right contrast is what
produces the print that most pleases you.  Some people prefer higher
contrast, while others prefer lower contrast - just like some people
prefer Chevies and others like Toyotas.

A second suggestion - stick with one paper and one brand of filters until
you are comfortable with the results that you are getting.  Then, if you
want to experiment, try a different paper.  But if possible, don't mix
and match filters.  If you take reasonable care of them, a set of
printing filters will last for years.

Louie

Variable-contrast paper should ALWAYS be used with a filter. To get a
grade 2, use the #2 filter, etc. NO FILTER gives about the same grade
1 1/2 filter.

Why do you think you have to put your question on paper? We don't
always need a hard copy.

Sorry about being late -- I am not a frequent visitor.

Correct!

...and you are not the only one. Many newbies seem to think of
variable paper contrast as a confusing silver bullit.

There is a lot of fuss about contrast. Sure -- knowing about
contrast is important but most negatives are ''normal''; ie you
can stick with ''normal'' paper contrast and, more or less,
forget about variable paper contrast.

Although they do not exclude each other I think it is easier to
learn about dodging and burning, and the reward is greater, than
to learn about contrast,

If there is a contrast issue for newbies it is often related to
over developed negatives.

I know I didn't answer you question but I wrote this with best
intentions.

Sincerely,
Jörgen

--
The road to hell is paved with good intentions.