Repairing microfilm

Gretchen Fulforth Stroh <gstroh1<-a t->swarthmore< . >edu> writes

>Simple (I hope) question:  How do you repair broken microfilm? We
>have discovered reels where the film is broken/torn apart.

Not so very simple.  Usually when people speak of broken films, they
are referring to "service" or reading copies.  By far the preferred
method in this case is replacement--locating the camera negative or
duplicate negative and having a new print made.  Presumably, this
new print would be on polyester film base, obviating breakage.

When this is not possible, or in cases where the broken film is a
camera negative, things get more complicated.  Refilming to
preservation standards is indicated for any material deemed to be of
lasting value, but when we arrive at the worst-case scenario--i.e.,
the broken film is the only surviving record--some kind of repair or
copying of this material is wanted.

There's only one case in which repair is simple and that is when the
break has occurred at an existing splice which is well clear of any
image material.  This relatively simple repair is resplicing.  When
the tear is across imaged film, you have real problems.  A fairly
common solution is to repair with transparent tape.  This is a bad
solution, from a preservation standpoint, as well as from the
standpoint of quality of the projected image, yet it is often done.
I suppose it is justifiable in cases where the service film is in
demand, has a known existing negative and/or originals corresponding
to it, and the institution holding the service copy lacks the budget
or time to replace it in time to fill the demand.  But in the
"only-known-copy" scenario, it is unjustifiable unless somebody can
tell me of a splicing tape known to be completely safe (the
adhesives in transparent tape generally are deleterious to the metal
silver image and I've seen many examples of tape *destroying* film.

A recent posting of mine briefly discusses a labor-intensive copying
method using a contact printing box. Camera copying, with subsurface
illumination of the broken film (also labor intensive), is possible,
too. No doubt there are people in one branch or another of photo
conservation out there who have other insights and ideas in this
regard.  It's best to search as exhaustively as possible for
replacements before you go mucking around with films.  You can
easily make a bad situation worse with brittle old films and it's
well to remember that physical repair of same followed by continued
use is likely to result in yet more breakage.

Charles Stewart, U.C. Berkeley

                                  ***
                  Conservation DistList Instance 11:49
                Distributed: Wednesday, December 3, 1997
                       Message Id: cdl-11-49-004
                                  ***