e the tracing is being
made, or while making the transfer copy from it; so that while it
serves as a guide to the general features of the original, it will
not, when tested, be an exact duplication. The danger of an exact
duplication is quite generally understood by persons having any
knowledge of forgery, and is therefore avoided. Another difficulty is
that the very delicate features of the original writing are more or
less obscured by the opaqueness of two sheets of paper, and are
therefore changed or omitted from the forged simulation, and their
absence is usually supplied, through force of habit, by equally
delicate unconscious characteristics from the writing of the forger.
Again, the forger rarely possesses the requisite skill to exactly
reproduce his tracing. Much of the minutiae of the original writing is
more or less microscopic, and from that reason passes unobserved by
the forger. Outlines of writing to be forged are sometimes simply
drawn with a pencil, and then worked up in ink. Such outlines will not
usually furnish so good an imitation as to form, since they depend
wholly upon the imitative skill of the forger.

Besides the forementioned evidences of forgery by tracing, where
pencil or carbon guide-lines are used which must necessarily be
removed by rubber, there are liable to remain some slight fragments of
the tracing lines, while the mill finish of the paper will be impaired
and its fiber more or less torn out, so as to lie loose upon the
surface. Also the ink will be more or less ground off from the paper,
thus giving the lines a gray and lifeless appearance. And as
retouchings are usually made after the guide-lines have been removed,
the ink, wherever they occur, will have a more black and fresh
appearance than elsewhere. All these phenomena are plainly manifest
under the microscope. Where the tracing is made directly with pen and
ink over a transparency, as is often done, no rubbing is necessary,
and of course, the phenomena from rubbering does not appear.

Where signatures or other writings have been forged by previously
making a study and practice of the writing, to be copied until it has
been to a greater or less degree idealized, the hand must be trained
to its imitation so that it can be written with a more or less
approximation as to form and natural freedom.

Forgeries and tracings made by skilful imitators are the most
difficult of detection, as the internal evidence of forgery by tracing