st ten diameters. In the projection method of enlargement, the
image is printed directly from the original negative, and the
preparation of an enlarged negative is unnecessary.

Aside from the photographic equipment, the needed materials are: a
roll of scotch photographic tape 1 inch wide to outline the areas of
the fingerprints on the negatives to be used; some stiff cardboard
approximately 1/32 inch thick on which to mount the prepared charts; a
tube of rubber cement; and a bottle of translucent ink, other than
black or white.

A light-box on which to view the negatives while blocking, and a
lettering set to draw the lines and numbers uniformly on the charts,
while not absolutely essential, are helpful conveniences. A light-box
is basically a frosted pane of glass with a light beneath it to
produce soft, even, non-glaring illumination. If no light-box is
available, a clear window may be utilized in "blocking" the negatives.

If the expert finds it necessary to have an outside source prepare his
photographs, he should retain personal custody of the evidence during
the operation.

The original latent print and inked print with which it is identical
should be photographed actual size. This procedure eliminates
guesswork in enlarging both to the same degree. Whatever areas of the
two prints are deemed requisite to illustrate the method of
identification are then outlined (blocked) on the negatives with the
masking tape, so that only those areas will show in the subsequent
enlargements. Generally, if the legible area of the latent print is
small, it is well to show the complete print. If the area is large,
however, as in a palm print, an area which will not make the chart too
bulky or unwieldy may be selected.

In blocking, the negative is affixed to the window pane or light-box
by means of strips of photographic tape across the corners, with the
side to be blocked up. This prevents constant shifting of the negative
while it is being prepared. The latent print should be blocked first.
Corners of the blocked areas should be square. Care should be
exercised to have as nearly as possible the same ridge formations
shown and the ridge formations in the same upright or horizontal
positions. This may be facilitated by fixing a negative, bearing ruled
squares, between the negative being blocked and the glass to which it
is attached.

If the latent print was developed or photographed as a light print on
a dark background, a