(2) Multiple drawings. When using this method, you create
separate drawings for each color. When preparing the drawing, you must
consider the value of the primary colors so when combined they produce
the correct shade of the secondary colors. For example, you must
consider the value on the red drawing and the blue drawing so the
correct shade of violet prints on the finished copy.
(a) Before you can draw the color separation drawings, ensure
you have two or more registration marks and crop marks on the original.
Then place an acetate sheet over the original, frosted side up. Then
add the registration and crop marks over the marks on the original.
Next you outline the areas containing the color for this plate, and fill
them in with India ink. To achieve lap register, the design of each
plate is slightly larger than the original to ensure a slight overlap.
The elements to appear in the lighter color should overlap into the
darker color. You would use this process for all three primary colors
and the black plate.
(b) Figure 227 shows an example of this process. The plate in
the upper lefthand corner represents the color illustration the
photographer must reproduce. You also should send this plate as a
reference the photographer can use for the finished print. As you can
see, this plate has three registration marks, crop marks, and dimension
instructions. The example this figure shows also includes a 30%
halftone plate that adds gray to some color areas. The photographer
combines the halftone plate with the black when making the black
Graphic overlays provide a means of presenting a series of ideas or
construction theory one step at a time. A map overlay presents the
current situation for a given area on a map.
a. Graphic Overlays. The use of overlays is an effective feature
of overhead projectors. By preparing separate transparencies, you can
divide problems, processes, and other types of information into logical
elements and show them progressively.
(1) Preparing overlays for viewgraphs. When preparing viewgraphs
using the overlay method, you must first make a sketch of the total
viewgraph. Then you must decide which elements you will place on the
base viewgraph and each overlay. Once you have determined the placement
of the elements, use the original to prepare the foils for the base
viewgraph and each overlay by copying the appropriate elements to each.