Photoshop CS3 for Screen Printers- P16 ppt

There are several problems that can occur whilescreen printing using a color separation performed by Photoshop; oneissue is that Photoshop might add a little more of one color, say cyan

1 Open the file Fish Picture.jpg from the Chapter 23 folder on the

companion CD

2 Choose Image>Canvas Size Change the image size to 18 by 25

inches If necessary, use the scroll bars to position the picture in themiddle of your computer screen

3 Select the Eyedropper tool and select the green color of the plate,

just behind the fish’s back fins

4 Select the Paint Bucket tool, and in the options bar change the Mode to Normal, Opacity to 100 percent, and Tolerance to 100, and verify that Anti-alias and Contiguous are checked.

5 Click in the newly added part of the canvas, outside the wall area

6 Select the Brush tool from the toolbox.

7 Select the Hard Round 19 pixels brush from the Brush palette in

the options bar

8 Paint with this brush very carefully around the outside of the fish.Change the brush and brush size as needed to cover over the rest ofthe flaws in the green part of the image

9 Save the image as Fish.psd (a Photoshop PSD file).

Text and Borders

You can add text and borders to finish the logo; however, we save thesection on text for later There are different ways to work with type in aPhotoshop image, and it deserves its own section In this section, let’sjust add a border

. Note:

If you want to skip this part of the exercise, the completed file is Fish3.psd

on the Chapter 23 folder on the companion CD Use the Zoom tool to

position the image appropriately on the screen

1 Open the file Fish.psd from the Chapter 23 folder of the companion

CD, or use the file you created in the last exercise Use the Zoom

tool to zoom in or out on the image

2 Use the Crop tool to crop the image so that it forms a more

propor-tional, rectangular shape Leave enough room for a border (If

desired, use Image>Image Size to increase or decrease the size of

the image.) Save the image to the hard drive as Fish.psd Your

screen should look similar to what’s shown in Figure 23-2

3 Choose the Brush tool from the toolbox.

4 Set Mode to Dissolve and Opacity and Flow to 100 percent Enable the Airbrush option.

5 Change the foreground color in the toolbox to white.

Figure 23-2: The Fish.psd file

6 Open the Brushes palette from the options bar From the additional

options, choose Faux Finish Brushes and click OK.

7 Choose Sea Sponge 2 and an appropriate brush number.

8 Paint around the image using this tool See Figure 23-3 I’ve added

some additional touches with the Grass Brush tool at the bottom of

the image The Grass Brush tool is available if you choose ResetBrushes from the additional options

9 Crop the image again if desired and save the image as Fish2.psd.

(You can see my Fish2.psd in Figure 23-3.)

When you are preparing an image for screen printing, you generally have

to perform manual and automatic color adjustments too These includeusing Filter>Sharpen>Unsharp Mask to sharpen the image and

Image>Adjustments>Hue/Saturation to saturate the image There areother things too; if you’ve been skipping around in this book, return toChapter 16 for other image preparation tasks Use your knowledge inthis area to further prepare the image before moving on After applyingUnsharp Mask and increasing the saturation, resave the file as

] Tip:

This particular image needs lots of unsharp masking and saturation

Chapter Project Part II: Perform the Separation

Once the image has been readied for print, you can perform the actualseparation The first step in performing this color separation is to changethe mode of the image from RGB to CMYK:

1 Open the file Fish3.psd from the Chapter 23 folder of the companion

CD, or use the file you’ve created in previous sections

2 Choose Image>Mode>CMYK Color You’ll be prompted to merge

the layers if you have more than one layer If this happens in future

work, click Merge.

3 Open the Channels palette with Window>Channels Now there are

four channels of CMYK and a composite channel See Figure 23-4

4 Save the file as Fish4.psd.

Figure 23-4: Viewing the channels

Chapter Project Part III: Correct Color

Your image is now color separated Performing this separation is as easy

as changing from RGB to CMYK However, correcting the colors afterconverting to CMYK is the biggest part of creating a good, usable pro-cess color separation There are several problems that can occur whilescreen printing using a color separation performed by Photoshop; oneissue is that Photoshop might add a little more of one color, say cyan forinstance, than you usually need when it creates the separations This is aproblem because, for example, printing cyan ink dots in an area that’ssupposed to print yellow will cause the color to come out all wrong atpress time Even a small amount of cyan (taking into account dot gain,screen tension, mesh size, and ink types) can cause yellow to go green.This same thing can happen with red Red is created with CMYKinks by printing yellow and magenta together If Photoshop adds a fewdots of cyan—and those few dots (with dot gain) turn into a hundreddots—the red color you are expecting at press time will be purple afterit’s printed

In addition to these types of problems, you might also need toincrease the black in the image This is useful if the image has a lot ofblack outlines in it, or if it consists of a lot of sharp edges After looking

at the design after the separation, you might also decide to add a spotcolor channel to it too Adding a spot color channel allows you to get thepure red, pure yellow, pure black, etc., while at the press

So, how do you go about correcting these issues? Well, it’s trial anderror and lots of practice and patience It’s also experimenting with yourequipment and inks to get to know them and what to expect In the nextfew sections we learn where to start to access the tools to correct theseissues, how to use them, and what the common tasks are

Throughout this project we perform a color separation that is intended forprinting on a white shirt Creating separations for other colors requires addi-tional techniques, as detailed in Chapter 25

Working with Colors

There are several ways that you can “clean up” the colors in your imagesbefore printing out the color separations You use two main palettes—theChannels palette and the Info palette—and you use two main tools—theCurves tool and the Selective Color tool Both of these are available fromthe Image>Adjustments menu choices Before continuing then, config-ure your work area to contain the Channels and Info palettes

] Tip:

If you worked through Chapter 5, you created a workspace named ScreenPrinter-based This is available from the Window>Workspace menu and

contains everything that you need

Use the Curves Tool and the Info Palette to Clean Up

an Image

Let’s experiment with checking and changing the colors in this imageusing the Curves tool and the Info palette

1 Open the Fish4.psd file that you created in the last section or have

obtained from the Chapter 23 folder of the companion CD

2 Position the Info palette near the image Click on the Eyedropper

tool in the toolbox Verify that all channels are selected in the Channels

palette.

3 Use the Eyedropper to check the white in

the thickest part of the border and see if it’s

really white; all of the numbers in the Info

palette should read 0 percent for the CMYK

percentages See Figure 23-5

4 Using the Eyedropper, hover over the center

of the fish’s eye where it is black Notice the

percentages in the Info palette Mixing the

four colors of ink will create this shade of

black (If you wanted to, you could create a

black spot color channel.)

5 Using the Eyedropper and watching the

numbers in the Info palette, move the

Eye-dropper over an area of yellow in the image

Choose an area in the fish’s bottom fin

around the black dots in that area Look at

the numbers in the Info palette and notice

some of the yellow parts of the fin have cyan

in them Because Photoshop has been known

to really exaggerate cyans when creating a

separation, and if you find this to be true

now, you should lower those numbers a bit

In a pure yellow, you should theoretically

remove all the cyan

6 To change the cyan, choose Image>Adjustments>Curves Choose

Cyan in the Channel drop-down list The changes you make now will

only affect the Cyan channel Because the other channels are visible

in the Channels palette though, you can see the effect of your actions

on the entire image

7 In the Curves dialog box in the bottom left of the grid, pull down theline a little, as shown in Figure 23-6 This will reduce the cyan in theimage

8 Use the Info palette to see if you’ve removed the cyan and gotten thepercentages down to 0 percent for (most of) the yellow part of the

Figure 23-5: When the Eyedropper is on a white part of the image, the CMYK values should all be 0%.

image Use the Info palette to look at the before and after numbersfor the cyan in the yellow See Figure 23-6.

View the composite to see what’s happening to the entire image See Figure23-6 Although the numbers never lie, reducing the cyan too much can

result in a washed-out image You’ll have to use your own judgment

9 When you’ve reduced the cyan and verified that the image still looks

as it should, click OK in the Curves palette Resave the image as

Fish5.psd.

You can perform the same operations on the magenta, yellow, and blackchannels if you feel it’s necessary You’ll have to experiment, print, andexperiment some more before you really understand the limits of yourinks, screens, equipment, and, yes, even Photoshop

] Tip:

The file Fish4 with Color Adjustments.psd on the companion CD is an

example of what your new file with color adjustments might look like

Figure 23-6: Tweaking colors

Use the Selective Color Tool and the Info Palette to Clean Up an Image

You can also use the Selective Color tool to work with specific colors in

an image The Selective Color tool allows you to work with specific ors—red, yellow, green, cyan, blue, magenta, white, neutral, and black.Let’s experiment with checking and changing the colors in thisimage using the Selective Color tool and the Info palette

col-1 Open the file Fish4.psd from the companion CD, or use the file you

created in the last exercise

2 Choose Image>Adjustments>Selective Color The Selective

Color dialog box appears, as shown in Figure 23-7

3 Choose Yellows in the Colors drop-down list.

4 Since yellow shouldn’t have any extra cyan in it, move the slider toreduce the cyan in the image Use the Eyedropper and the Info pal-ette to see the before and after values for cyan You can removevirtually all cyan from the yellows in the image Check and uncheckthe Preview box to see the difference Try not to go overboard;reducing cyan too much can substantially change the look of theimage

5 While still on the yellows, increase the magenta and yellow sliders.Use the Info palette to see the change in the values

6 Choose Reds in the Colors drop-down list Position the Eyedropper

on the fish’s lips Red is made from magenta and yellow Move thesliders to remove the cyan, and boost magenta and yellow

Figure 23-7: The Selective Color dialog box

7 With the Eyedropper positioned over the fish’s lips, view the

changes for cyan and other colors using the Info palette The Infopalette should read 0 percent for cyan in the fish’s lips Use the Pre-view check box to see the before and after

8 Choose Magentas in the Colors drop-down list Position the

Eye-dropper over the fish’s eye, where the eyebrow is (supposedly) puremagenta Notice there is a bit of cyan in there

9 Use the sliders to reduce the cyan and up the magenta until you get apurer color Check and uncheck the Preview check box to see thechanges Use your best judgment as to when “enough is enough.”

10 Choose other colors in the Selective Color dialog box and view theirnumbers You’ll learn a lot about how colors are created using theEyedropper and the Info palette For instance, green is made fromyellow and cyan; thus, when hovering over a green in the image,you’ll see higher numbers for these two components

11 When finished, click OK Save the file again as Fish5.psd.

The Selective Color command is a powerful part of Photoshop and allowsyou to work with and adjust colors independently of one another Under-standing what colors are created from what combination of CMYK willhelp you use this tool more effectively For practice, open a colorfulimage and use the Selective Color command, the Eyedropper, and theInfo palette to note how specific colors are created

Chapter Project Part IV: Additional

Techniques

When creating process color separations, there are a few other thingsthat you can do besides the actual separation and color correction Often,

a spot color channel is added, especially if you want to bring out a color

or there is a lot of a specific color in an image

Create a Spot Color Channel

If you want or need to, you can create a spot color channel for any cess color-separated image Creating a spot color channel is done thesame way as was detailed in Chapter 22 To create a spot color for theimage that we’re working with in this chapter:

pro-1 Open Fish4.psd or Fish4 with Color Adjustments.psd from the companion CD, or use the Fish5.psd file that you created in the pre-

vious section

2 Choose Select>Color Range.

3 Check the Invert check box and verify that Selection is checked and None is showing in Selection Preview.

4 In the Select field, choose Sampled Colors Make sure Selection is

selected

5 Use the Eyedropper to click on the fish’s red lips in the image Usingthe Info palette, write down the percentages for the C, M, Y, and Kvalues Now, let’s make a spot color channel for the red in this image.See Figure 23-8

Figure 23-8: Creating a spot color

6 Use the Fuzziness slider to select the red, as shown in Figure 23-8.

Click OK.

7 At the bottom of the Channels palette, click the Save selection as

channel icon.

8 Click on the new channel in the Channels palette

9 Choose Select>Deselect (You might have to clean up the channel

some, as detailed in Chapter 22.)

10 Double-click in the New Alpha channel icon, not the name, to open

the Channel Options dialog box

11 Select the Spot Color radio button in the Channel Options dialog box Change the name to Red Spot Color in the Name field, and change Solidity to 30 percent.

12 Click on the color square and choose a red from the Color Picker thatmatches the red in the image If you can’t see the color anywhere onyour screen, type in the CMYK values you copied in step 5 Click

OK twice.

13 In the Channels palette, click on the composite channel so that youcan see the entire image All of the channels should have an eye bythem, except for the new spot color Notice how red the reds are inthe image

14 Click in the Channels palette to view the red spot color along with

these Click the eye icon to remove it Notice the difference Whenscreen printed, this red will show up much better and be morerobust

15 Save the file as Fish6.psd.

Color separations like the one we’ve done in this chapter are for whiteshirts Note that the fish image has white in it The white in the shirt willcreate the white in the image If you are going to print this on anothercolor of shirt, you will need to create a white plate (which is like a spotcolor for the white in the image) so that the white you want will actually

be white on the shirt Chapter 25 introduces you to creating color tions for darker shirts, but for light shirts like off-white, neutral, light tan,gray, etc., the following should work fine

separa-To create a white plate (also called a negative white plate or whiteprinter):

1 Using the Fish6.psd file, duplicate the file using

Image>Dupli-cate Click OK to accept the default name.

2 Select the Magic Wand from the toolbox Change Tolerance to 15 and leave Contiguous and Anti-alias checked.

3 Change the background color in the toolbox to black.

4 To create a mask around the image, click on a white area around theoutside of the file to select it You can verify you’re selected truewhite from the Info palette; all CMYK values should be at 0%

5 Use the Magic Wand as many times as needed to delete any tional white areas around the edges of the file

addi-6 Choose Select>Deselect You’ve created a mask around the image.

7 Choose Select>Color Range.

8 Use the Eyedropper to select a white part of the fish The best area

is around the gills and face area

9 Move the Fuzziness slider so that you pick up the white that youwant, without picking up so much that you’ll fade out the image

13 Select the Spot Color radio button.

14 Use the color square to choose white for the color Click OK.

15 Drag this new white channel to the first version of the file, and drop

it there

16 Close the duplicate file without saving

17 Place eye icons next to all of the channels in the original file to see

the result Save the file as Fish7.psd.

If the file doesn’t look as it should, continue on to the next section.There, you can configure the channels in the order that they’ll be printed

on the press

View the Final Separation

If you are printing on a light-colored shirt instead of a white shirt, youcan simulate the shirt color while viewing the final separation to see how

it might look once it’s printed You can also change the order of the nels to help you stack the channels the way you’ll print them on thepress These things can’t be done in CMYK mode though; you’ll have toconvert to Multichannel mode

Before changing to Multichannel mode, make sure you’re finished with thecomposite channel Once it’s converted, there will no longer be a compositechannel available, and you won’t be able to create any more spot colors orwhite plates

To convert to Multichannel mode, change the order of the channels, andsimulate a T-shirt color:

1 Open the file Fish6.psd or Fish7.psd that you created in the last

section, or open the file from the companion CD

2 Choose Image>Mode>Multichannel Notice that the composite

channel is gone and that the file doesn’t look as it should

] Tip:

Your file might not look so great your first time through these exercises

Learning to create the right mix of colors takes time Additionally, monitor

calibration, the output device you are using, inks, screens, and other items

can interfere with a good output

3 Rearrange the channels If you’ve created a white plate, drag thatplate to the top of the list

4 Place the yellow second, then magenta, then the spot color, thencyan, and then black You are now previewing in correct print order

5 In the Channels palette, click the additional options arrow and choose

New Channel This new channel will represent the T-shirt color.

6 Name the new channel Shirt Color.

7 Click on the color square to bring up the Color Picker Choose theappropriate shirt color from the Color Picker dialog box

8 Click OK twice.

9 In the Channels palette, drag this new channel to the top of the nel list.

chan-10 Show the eyes in the Channels palette to see all of the channels Byremoving the eye icon from the shirt color channel, you can see whathappens to the colors in the image

11 Save your new image

This ends the introduction to process color separations The steps arebasically the same for any image that you might have, although the actualvalues and amount of tweaking you do will differ

The image chosen for this chapter was selected for its range of colors, not

for its ability to be screen printed easily Screen printing process color rations takes testing, practice, and familiarity with your equipment and inks.The image might look off-color when viewed on your monitor or when

sepa-printed using your equipment

Working with Vector Type Layers

You might have noticed that we didn’t add any text to the image we’vebeen working with in this chapter That’s because there are two differentways to work with type, and the subject deserves its own section Typecan blend in with the image on a process color print and have type effectsapplied, such as a drop shadow and gradients, or type can stand on itsown away from the image and look and act like a spot color Type thatblends in with the image in a process color print is printed as halftones;type that does not blend and stands on its own can be printed as a vectortype layer Vector type layers are the optimal choice when possible,because they are printed as vector data and are thus much cleaner, lesspixelated, and a whole lot easier to screen print than rasterized data

If you are working with a piece of artwork in which the text blendswith the image, just work with the text as you would with any other pro-cess color image You don’t have to do anything special If, however, yourtype stands alone, as it will in the procedure shown in this section, youcan configure it so that it prints as vector text