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Re: Print struck from Nitrate?


At last there is something on this list that I really know something
about.  I am not a colorist but subscribed to the list because I work
with a colorist and manage the operations of an archival videolab.  I
have however worked for ten years examining, repairing and restoring
old nitrate and safety films.  The situation you describe I am quite
familiar with.

The Finegrain safety material which would have had the word NITRATE
printed on the side because of print through is correctly claimed,
however as it was probably printed directly from the original camera
negative NITRATE should have appeared as white writing on the fogged
edge of the finegrain.  If you were to print a negative from this
Finegrain the word NITRATE would be printed through again and would be
black. So long as the finegrain was printed on to raw stock which has
been pre-exposed with the manufacturer's marks, including the word
SAFETY, it will indeed be on the side, or margins.  Not every
manufacturer prints details onto their raw stock, Agfa being an
example.  Kodak do, and once the finegrain has been created it has
been my experience that the word SAFETY can be very difficult to see.
One is looking for black writing on the fogged margin.  It takes a
loup, a light box and persistence to find.

So how do you tell if it is Nitrate or Safety that you are dealing
with?  The only reliable method is to go to the head or tail of the
film cut off a useless strip one perforation wide.  Bend it in the
middle so that it makes an A shape, place it on the ground (outside or
in a well ventilated, or exhausted, space) and set light to it.  If it
is nitrate it will burn vigorously once the flame has taken.  If it is
Safety the flame should never take, if you remove the flame the film
strip will simply stop melting.

There is no reliable non-destructive method that I am aware of.  We
did use a sink or float test for a while but it proved unreliable.
Once again one has to remove a piece of the film and drop it into
trichlorethylene (very nasty solvent).  If it floated it was supposed
to be safety and if it sank then it was nitrate.

Hope this has been a help,

Bruce Langner
National Film & Sound Archive

--- End of forwarded message from Bruce Langner/Acton/NFSA <Bruce_Langner at nfsa.gov.au>