Lawley Clips

The light change signal in this method, which
was used on Lawley printers, used for 30 years throughout the English-speaking world, is provided by small metallic clips inserted between two
perforations on the original material. The disadvantages of this method
were that there was a risk of perforation damage in the original and
there was a lot of intensive preparation work. This method has not
been used for many years. Many archives and film collections have
negatives with these clips and to ensure the safety of the film and
of another printer they have to be removed before the film can be
printed. Removing Lawley clips can be a tedious and risky exercise as
the film can be damaged around the perforations during the removal.
Lawley made a small hand device for the purpose, which is hardly seen
anymore. In any case, the device was not as quick or as safe [to the
film] as an experienced operator with a pen knife!