Spot Color Separation
|Spot color separations
are usually done in vector programs like Adobe Illustrator, Freehand or
image is complicated or supplied in CMYK format these spot color logos
and clipart images can be difficult and time consuming to separate.
For this example we deliberately made a low quality ink jet print of the "T-Shirt Crest" logo onto a sheet of paper then scanned it back into Photoshop at 300dpi. The image was scanned at a high resolution to get as much information as possible.
Obviously if the printed
copy your customer brings in is of low quality it will always be difficult
to produce anything acceptable.
|Step 1 Preparation
In Photoshop navigate your way to the Tutorials folder on the EasyArt CD and double click the file "T-Shirt Crest", this is the scanned image of the logo that was printed out on to paper.
The colors in this scanned
image are very flat, by increasing the image contrast and intensity,
the individual colors will be easier to select.
To improve this image ready for separation go to the yellow action buttons and click "Increase Brightness", then "Increase Brightness" again, next click "Increase Color" twice, then finally click "Improve Image RGB".
The image is now ready
to separate into 5 spot colors, Red, Blue, Brown, Yellow and black.
In the "Color Range" window
that appears make sure the "Select:" drop down box reads "Sampled Colors"
and "Selection" is checked.
You will notice the mouse pointer has changed to the "Eye Dropper" tool. Click on a red part of the design.
|The areas of
red in the design will now appear in the "Color Range" window.
With the mouse pointer drag the "Fuzziness" slider left and right, observe how the amount of red being selected changes as you drag.
For this color move the "Fuzziness" slider to the far right (200) and click OK.
A "New Spot Channel" window will appear, type in "Red" and click on the "Color" box and change the color to red. (RGB values - R=255, G=0, B=0) then click OK.
This will bring up a message
window asking you to select another color click continue.
In the "New Spot Channel" window that appears type in blue, then click on the small gray square next to the word "color" and the "Color Picker" window will appear. Go to the RGB section and type in these values for this blue. R = 0 G = 54 B = 255 then click OK.
Repeat these steps until
you have selected all 5 colors.
when you have selected all 5 colors click on the stop button when asked to select another color.
You will notice the "spot color separation" button has turned red, scroll up the Actions List and click on the pale red button "Reset".
|Step 3 Adjustment
With the 5 different spot colors separated there is still quite a bit of work to do before they are ready to use.
Go to the channels list and select the "Black" channel and turn off all the other channels.
|Looking at the
"Black" channel you can see some of the brown areas of the eagle are appearing
in this "Black" channel.
Obviously you don't want this to over print the brown, so those areas must be removed from the black. Before doing that select the "Brown" channel. (or what ever you called that color).
||With the "Lasso"
tool make a selection around the wings and body of the eagle.
On the menu bar at the top of your screen go "Selection > Inverse", this will invert the selection.
Next on the menu bar again go "Edit > Fill" and in the "Fill" box that appears select 100% white. Then go "Select > Deselect" This will remove (erase) all the unwanted pixels that were selected when making the "Brown" spot color.
Still on the brown channel go to the actions list and click on the green button "Increase Color in Channel" twice. (this will strengthen the color)
the "Black" channel. Go to the green action buttons and click
"Apply 'S' Curve". This will make the light areas lighter and
the dark areas darker.
With the black channel still selected go to the menu bar at the top of your screen and click "Select > Load Selection"
In the "Load Selection" window that appears select "Brown" (or what ever you called your brown channel) in the "Channel:" drop down list. Click OK
Notice now all the areas
of "Brown" are selected in the "Black" channel.
Select the "Red" channel,
go to the actions list and click on the green button "Apply 'S' Curve"
this will strengthen the colors and remove any light pixels.
|Turn on all
color channels and zoom in close to the image and you will see there is
a slight gap between the individual spot colors and the "Black"
There are two ways of filling in this gap. The first is to add "Trap" to the "Black" making it overprint the colors, the second is to add "Trap" to each of the colors, making them print slightly under the "Black". (recommended)
For this image you can
use both methods.
Select the "Yellow" channel and click on the green button "Add Trap to Channel"
Select the "Brown" Channel" and click on the green button "Add Trap to Channel"
Select the "Black" Channel" and click on the green button "Add Trap to Channel"
The "Blue" and "Red" channels don't need any "Trap".
For this example the Black areas of the design will not be included in the White base.
Yellow channel and drag it onto the small page icon at the bottom of
the channels list, to duplicate it.
With the white base channel selected, hold down your mouse button and drag up the channel order until it sits just below the "Shirt Color" channel.
the Ctrl key on your keyboard ("Option" key on the Mac) and
click on the red channel.
Hold down the Ctrl key again and click on the brown channel, fill that selection with black, then do the same for the blue channel.
the new white base, change the shirt color to Dark Green.
a white base that is slightly smaller than the colors you are printing
on top, select the white base channel, then click on the green EasyArt
button "Choke it!".
There may be some areas you want on the white base that you were not able to select from one of the other color channels, you will have to add these in manually, by either making a selection and filling with black or by using one of the brush tools with a black fill.