(3) Automatic exposure times can be set from a fraction of a second
to several minutes by means of a timer attached to the printer.
(4) In addition, most printers are equipped with a sheet of diffusing
glass, located between the lights and the negative when the lights are
turned on. Above the diffusion glass is a thick sheet of plate glass on
which the negative is placed, emulsion side up.
on the type of equipment used in the process.
(1) Clean the printing area before starting other operations. Remove
all dust, lint, dirt, and other foreign matter from the printing area. When
possible, use a vacuum cleaner, as dusting causes the material to become
airborne, and it soon settles back into the working area.
(2) Connect the projection printer to the timer. Turn the printing
light on and make sure the area illuminated by the projected light is large
enough to cover the entire printing frame as shown in Figure 22. Allow a
generous coverage of light in case you misalign the printing frame.
(3) Clean the negative to be printed, making sure it is free of all
dust and lint.
(4) Place the negative with the emulsion side up on the face of the
printing frame's glass surface. For a professional appearance, when
contacting more than one negative or strip of negatives on the same sheet of
paper, be sure the subject matter is facing the same direction. With roll
film there is a frame number located below each negative. When the
negatives are positioned on the glass, the lowest numbered negative should
be located in the upper right corner. The highest numbered negative (last
frame of the roll) should be in the lower left hand corner. Since the film
is placed on the glass emulsion up these numbers will appear backwards when
viewed from this position. Refer to Figure 22 for an example of the proper
placement of the negatives.