At a color separation objects which partially superimpose each other, can be arranged on color-splitted bands by following methods.
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Color of the upper object is surprinted (overprint) in the field of overlapping on color of the lower object without removal last (look the previous section). |
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Color of the lower object in the field of overlapping can be deleted (knockout). |
The first variant is peculiar only for the press ?????????? colors when each color is printed special ???????? by color.
And the second variant is characteristic for printing by triad colors (blue, magenta, yellow and black) which, being the put small points, at physical and optical superimposing form diversity of color.
For color ????????? the press the great value has accuracy of superimposing of prints of various color in the led out boundaries ? so-called ' ???????? "(registration). At adjoining objects of different color incorrect ???????? creates the empty not sealed gaps, on the one hand, and unreasonable"????????"? with another.
In practice of polygraphic processes it is possible to reduce considerably possibility incorrect ????????, but to bring it to naught it is unreal, the technology ????????? (trapping) ? small magnification or reduction of the area of object to compensate shift during printing of printing forms rather each other (fig. 16.6) therefore is developed.
In Adobe Illustrator program following methods of creation ????????? are used.
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By means of button Trap (????????) palettes Pathfinder (Handling of circuits) it is fulfilled automatic ???????? for the image consisting of simple objects. This method is not intended for such difficult objects, as the graded-index and decorative filling, the imported pointwise drawing. The information look further in section "Button Trap" of this chapter. |
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???????? forms at the expense of change of a thickness of a circuit of separate objects by means of palettes Stroke (Line). About it look more low in section "Obtaining ????????? by means of superimposing" the given chapter. |
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| Rice 16.6. The press without ????????? and with usage ????????? (in a central picture the circle extension, sufficient for error compensating ???????? is shown) |
If objects which are superimposed against each other, have the general colors for such objects ???????? most likely it is not required. For example, the first object contains 30 % of magenta and 90 % yellow (the pleasant it is light-ohristyj color), and the second object ? 60 % of magenta and 20 % black (not less pleasant violet color) in between not sealed space cannot appear, at the worst can appear a magenta gap as magenta color is the general for both objects.
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| Rice 16.7. Exterior ???????? (the smaller object extends) and internal ???????? (it is narrowed down ??????? object) |
If colors of adjacent objects absolutely different it is required ???????? which happens two types (fig. 16.7).
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Exterior ???????? (spread) which expands boundaries of light object against a dark background for support of small overlapping. |
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Internal ???????? (choke) which moves boundaries of a light background in dark object for creation of small overlapping. |
To fulfill ???????? follows at the most final stage as any transformations will influence value ????????? (for example, object scaling causes proportional change and for value ?????????) that, certainly, it is undesirable.
At application ????????? in a case superimposing of two light objects in the field of superimposing more dark boundary or boundary of other contrast color that does not enter at all into intentions of the designer can be formed. For example, light yellow and light blue objects can ????????? form a bright green band in area.
For preventing of it it is necessary to reduce percentage of color in area ????????? (in the given example ? yellow color), beforehand consulted with experts of the polygraphic enterprise.
???????? a font
The font placed within images, represents the considerable difficulty for the press. Especially attentively it is necessary to concern a small size.
It is necessary to avoid layout of a small size in images which are exposed to rasterization.
???????? a small print in ????????? the press at the slightest error ???????? also creates the unreadable text. If the font of dark color is printed on a color background it is necessary to prefer overprinting (overprint). The simple decision in this situation is more effective.
If the type size exceeds a certain limit it is possible to fulfill ???????? a font, placing its copy under the original and increasing a thickness of a circuit by certain value.
Eventually, the font by means of command Create Outline (to Transform to circuits) can be converted menu Type (Text) in curves and to apply to it ????????, as to any graphic object. Certainly, possibility of editing of the given object as text, and also advantage of a font will be thus lost at rasterization which are provided to it with technology ?????????? (hinting).
Button Trap
By means of button Trap (????????) palettes Pathfinder (Handling of circuits) which is caused on the screen by command Show Pathfinder (to Show handling of circuits) menu Window (Window), it is possible to fulfill automatic ???????? simple objects. Function consists that the program finds Light objects in the image, irrespective of their layout (in image quality or a background), and applies to them the installed parameters ?????????.
If two superimposed objects appear light color, the program uses ????????'??????? in color to prefer one of objects. If program "decision" not seems to the user satisfactory, by means of flag Reverse Traps (Inverse ????????) in dialog box Pathfinder Trap (Handling of circuits: ????????) it is possible to change a direction ?????????.
For performance ????????? it is necessary to select two or more objects and to click on button Trap (????????), the program displays dialog box PathlMer Trap Handling of circuits: ????????) (fig. 16.8).
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| Rice 16.8. Button Trap and dialogue o??? Pathfinder Trap |
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In the field Thickness (Thickness) is set value ????????? in a range from 0,01 to 5000 points. Value should be coordinated it with experts of printing house. |
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Field Height/Width (Height/width) serves for ratio determination ????????? but verticals and across. Setting of the given value can be caused necessity to compensate, for example, a non-uniform stretching of a paper across and on a vertical in the course of the press. ???????? it should be coordinated with experts of printing house. Value by default 100 % assumes identical value ????????? in both directions. To increase ???????? across, it is necessary to install Value of more than 100 % (but no more than 400 %) and to reduce ? value of less than 100 % (but not less than 25 %). |
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In the field Tint Reduction (Clarification) it is possible to install value which provides change of a color shade of area ?????????, applied to light object. Value of 40 % by default is accepted. |
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Flag Traps with Process Color (composite colors) provides with Trepping color hue converting in area ????????? in an equivalent of triad color (in parameters of color model CMYK), It should promote ?????????????? appearances of another ?????????? colors at a color separation. |
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Flag Reverse Traps (Inverse ????????) provides direction change ????????? (not at more light, and at more dark). This function is not spread to objects with so-called "saturated black" (Rich Black) ? the color containing besides black any an amount of blue, magenta and yellow colors. |
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Button Defaults (By default) allows to recover the values accepted by default. |
If more exact is required control ??????????, than it allows button Trap (????????), or ???????? difficult objects it is possible to fulfill ????????, changing parameters ??????? objects.
For this purpose it is necessary to select the upper object from what should "participate" in ?????????, and then by means of command Show Stroke (to Show a line) menu Window (Window) to cause on the screen palette Stroke (Line) with which help it is possible to simulate ????????.
To create exterior ???????? (spread), it is necessary to appropriate ??????? the same parameters of color, as at object filling, and also to increase/thickness ???????.
To create internal ???????? (choke), it is necessary to appropriate ??????? the same parameters of color which the background object has, in this case at object color parameters ??????? and filling will be various.
In the field Weight (Thickness) it is necessary to install value of a thickness ???????, ¦ in a range from 0,6 to 2,0 points, considering that ??????? in the thickness 1 blows ?I creates value ????????? half this value. Exact value j ????????? follows ???????????'?? experts of printing house.
Then it is necessary to activate palette Attributes (Attributes) and to install i flag Overprint Stroke (line Superimposing) that provides in exterior in, internal ?????????? the press with superimposing in the specified areas.
To create ???????? at ???????, it is necessary to select I correspond - ??? object, then in palette Stroke (Line) to appropriate ??????? white color and to install a necessary thickness. By means of command Copy to (Copy) menu Edit (Editing) it is necessary to copy a circuit in a clipboard, and then to execute command Paste in Front (to Paste forward) menu Edit (Editing). ????? a circuit it will be placed over the original and it is selected.
By means of palettes Stroke (Line) it is necessary to appropriate necessary color and a thickness, and a thickness should be more former on value idle talk-pjnga. Then it is necessary to activate palette Attributes (Attributes) and to install flag Overprint Stroke (line Superimposing).
To fulfill ???????? not at all object but only at its part, it is necessary to arrive as follows: to create a new circuit along a line assumed ?????????, and then to fulfill the same operations, as in the previous case.