ONYX White Paper White Ink Workflow. October White Ink Workflow From Design to Print

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1 ONYX White Paper October 2010 From Design to Print This document contains information on designing white ink data in Adobe Photoshop or Adobe Illustrator. The main focus will be on the white ink workflow, but the same information applies to using any spot ink channel. Some terms used in this document need to be clarified first. These are Spot Ink Channel, Spot Color, Channel, and Spot Separation. Spot Ink Channel is a color on the printer that is not treated as a process color. This includes white, gloss enhancers, varnishes, violet, and other non-cmyk inks. Spot Color is a specially named color that has a specific l*a*b* value. In working with white ink, spot colors are used to define where the white ink will be placed. Channel: In Adobe Photoshop a channel is a color within the current working color space. Like spot colors, custom channels are used to define where our white ink data will be placed. Channels have the ability to be either set as an alpha channel, or a spot color. Spot Separation is the plate assigned to the spot color. In a separation file each color will have its own plate. Documents in CMYK will have four plates. When a spot color is used, the separation file will contain a spot separation for each spot color. A CMYK+ Spot color document will have five plates. I - Designing in Photoshop In Adobe Photoshop, white ink data is defined by custom channels. There are two ways to set up custom channels. Both will be discussed below. First, create or load an existing job. Next, create a new channel ( this option is not visible, go to the Window menu and choose Layers. ). This option is located in the Channels tab next to Layers. If Image 1: Channels 1

2 When a custom channel is first created, the options for a name, color and opacity will be shown. If this does not appear, simply double-click on the new channel to bring up the options. The color and opacity are a representation within the application only. The user will determine those settings. The name of the channel can be anything. When the final output file is going to be a PDF, the name of the custom channel will be important. More on this will be discussed later. Using a TIF as the output file type, the channel name has no impact, but the order of the channels does. This is only a concern if the job has more than one custom channel. More detail will be provided later on. After the custom channel has been created it will be visible in the Channels tab. By default the channel is not visible. To enable it, simply click on the square next to the name. Once it is visible, the current document will show 100% coverage of the channel, based on the color assigned to it. A - Channels as Spot Colors When outputting a PDF file, the custom channel must be set to a spot color. Double-click on the custom channel, or choose Channel Options from the Channels menu. Channel Options window appears. Image 2: Additional Channel Options The Color Indicates region now lists Spot Color. Selecting this option will turn the custom channel into a spot color when the file is saved out as a TIF, or PDF. After selecting Spot Color as the option, only using Undo (Crtl-Z or Cmd-Z) will release the change. In the Save As dialog, options underneath the File Type list will be listed. The options available will depend on how the custom channel is configured. One of the listed options is Spot Color. This appears when the custom channel is set to Spot Color. By default this option is checked. The file can be saved out as either a TIF or a PDF file. 2

3 Image 3: Save As Window For ONYX to automatically assign the spot color the spot ink channel, the spot color name must be Spot1. Other names will result in additional steps that must be completed for the spot color to be properly assigned. These steps will be outlined in Section III. B - Channels as Masked Area (Alpha Channel) In addition to spot color, the custom channel can be set to represent an alpha channel. An alpha channel is detected by ONYX and automatically assigned to the media s spot ink channel. This option will only work with TIF output files. The option is selected by default when the custom channel is first created. The option is listed under Color Indicates section as Masked Area. In the Save As window, Alpha Channels is now available to select and is enabled by default. C - Designing Your Channel Designing within a custom channel is like using a Layer Mask, except black indicates data for that channel and white indicates no channel data. The same tools and filters that are available for Layer Masks are also available when editing a custom channel. D - Advantages and Disadvantages to Either Workflow There is little advantage to using either spot colors or alpha channels. Both workflows require the same amount of work and produce the same results. When defining a custom channel as a spot color, the name of that custom channel will impact how it is interpreted in ONYX. For names other than Spot1, this will create additional steps that can be automated in ONYX. Using the spot color workflow, images can be exported as either a TIF file or a PDF file. Defining a custom channel as an alpha channel (Masked Area) is automatically picked up by ONYX. Names do not matter, but the order listed in Photoshop does. This is only a concern if the image contains more than one custom channel. This workflow allows the images to only be exported in a TIF file format. 3

4 II Designing in Adobe Illustrator A - Spot Colors In order to create white ink data for an image in Adobe Illustrator, spot colors are used. Spot colors are created from the Swatches window. If the window is not visible, go to Window and choose Swatches. Click on the new button ( ) to create a swatch. The first field in the window is the name. Just like in Photoshop, the name of the spot color is important. For ONYX to automatically assign the spot color to a spot ink channel, name the color Spot1. Other names will require additional steps to work. More on this will be discussed in Section III. Below the name is the Color Type. This must be set to Spot Color. Image 4: New Swatch Window Next, select a color that will represent the spot color in the current job. It is recommended to use a color not currently used in the image. Once the spot color has been created, the white ink data can be added to the image. When designing, there are some important design standards that need to be applied for the white ink data to be retained. The first item involves spot color objects overlapping with non-spot color objects. If desired output requires both objects to be retained, the attribute, overprint, will need to be applied. Overprint is applied on an object to object basis. It is found in the Window menu under Attributes. The options, Overprint Fill & Overprint Stroke, will be available depending on the characteristics of the selected object. In all cases with spot color objects, the spot color object must be above the process color objects. Image 5: Overprinting If objects overlap in Illustrator, the output file will drop the overlapped portion of all objects underneath the top object. The overlapping portion creates a cut out and only the top object remains intact. With overprint enabled, the object below will be retained. Image 6 shows what happens to the output file with overprint on and off. 4

5 Image 6: Output With and Without Overprint Overprint is only needed when the white ink data on top overlaps color data. As mentioned previously, in order for the white ink data to be recognized properly it must be above the non-spot color objects. Does placing the white ink data above the rest of the artwork impact the final result? The only impact this has is that it will retain the white ink data as well as the artwork. The ability to control how the white ink prints underneath or above is controlled either in the ONYX RIP, or on the printer s panel. In most cases it can be controlled in ONYX. This varies depending on the printer. This topic will not be covered in this document. When the image design is complete, the next step is to output the artwork. With Adobe Illustrator this can be done as either a composite or separation file. B - Saving the File Composite File Composite files are the most commonly used type. They contain all color data for an image on a single page. The file is simply saved out as a vector file (PS, EPS, or PDF). When outputting the file, it is important to remember that of the three file types, only PDF can support transparency. If white ink or any spot color data crosses the transparency bounding box, that spot color data is rasterized. White ink will not be detected in those regions. Using a PDF 1.4 or higher without PDF/X will keep the transparency alive. It is recommended to use a 1.6 or 1.7 version. C - Saving the File Separation File In addition to composite files, Adobe Illustrator provides the options to output files as separations. Separation files take the color data and create multiple pages (plates), one for each color channel. A job designed in CMYK will contain four pages. Jobs containing spot colors will have an additional page per spot color. Image 7: CMYK Separation File Viewing a separation file will be limited to one channel per page in black and white. Each page will reflect where that particular channel contains data and where it does not. The image above shows what the initial composite file looks like and what would be seen on each page. 5

6 The ability to output a job as a separation file is found under File > Print. In the Print window change the printer to Adobe PDF. Image 8: Print to PDF - General Once selected, the options in the window will change. The image preview will usually not be correct. Depending on the size only part of the image or a lot of white space around it will be shown. The Adobe PDF printer, by default, uses a standard page size like letter or Defined by Printer. To adjust the image to the correct art board size, go to Media and change the Size to Custom. This will change the page size to match the art board size. The next step is to set the output to print a separation PDF. This is found under the Output, option is located to the upper left of the Print window. 6

7 Image 9: Print to PDF - Output Click on the Mode drop-down menu and select Separations (Host-Based). Once selected, the Document Ink Options will become available. The document will be broken up into the color space channels plus spot colors. Next to each of the colors listed are and icons. These icons are used in Adobe Illustrator to designate between spot colors ( ) and process colors ( ). The above example shows the standard CMYK color channels and one spot color. The output of this image will be a five-page PDF. Do not Convert All Spot Colors to Process, otherwise the white data placed in the image will be lost. The spot colors will be merged into the CMYK components. In the Mode drop-down menu, there is an additional separation option In-RIP Separations. There is an important difference between the two types of separations. When Separations (Host-Based) are used, the host computer does the separations. This means the file is outputted as separations as it leaves Illustrator. Using the second option, In-RIP Separations, means the file is outputted as a composite file and the separation will be created on the RIP side. To use separation files to generate white, the file must be a separation before it is loaded in the ONYX software. ONYX will combine the pages together. In addition to creating separation PDFs, Illustrator can also save separation PostScript files. To do this, the printer selected should be Adobe PostScript and not Adobe PDF. The remaining steps are the same as described above. Please visit for more information on separation files and the options available. Like all file formats there are advantages and disadvantages to using separations. In some cases applying transparency effects to white ink objects can have problems rendered under a composite file. Separation files are the best workaround in those cases. Separation files are spot color name independent. ONYX will automatically take the spot separation and assign it to a media spot ink channel. The downside of separation files is using additional spot colors not assigned to a spot ink channel. When this happens additional work is needed in ONYX to tell it to map your spot separation to the correct spot color. There is also a maximum separation limit of 12. This value is the sum total of process colors plus spot colors. We will not be discussing these steps in this document. If you are using additional spot colors in your image, you will want to use a composite file. 7

8 III How It Comes Together in ONYX After designing, the next step is to get ONYX to properly manage the file with white ink. The methods used are dependent on the type. Some methods do not require any user intervention, other than opening the file. Some require settings to be configured. This is done either in the Quick Set or in Preflight. For files coming from Adobe Illustrator, it is important to make sure overprint is enabled in the Configure RIP Options. This dialog is found in the RIQ-Queue, under Setup > PostScript > Configure RIP. Place a check mark next to Overprint. This option affects PS, EPS and PDF files. Under X10, the overprint option is automatically enabled for PDF files. The option in Configure RIP still needs to be enabled for EPS and PS files. Without the option enabled, all overprinted elements will not be rendered correctly. A - Loading a TIF with Alpha Channel or Spot Color TIF files with an alpha channel simply need to be loaded. ONYX automatically takes the alpha channel and assigns it to the spot ink channel. When dealing with multiple spot ink channels in ONYX, the order of your custom channels (alpha channels) from Photoshop will impact the automatic assigning done by ONYX. For example, your media has an ink configuration CMYK Gloss and White. When the file comes into ONYX, the first custom channel in your image will be assigned to the gloss spot ink channel. The second custom channel will be assigned to the white spot ink channel. The order of your custom channel should match the order of the spot ink channels. There is no way to reorder the spot ink channels in ONYX. If the order is incorrect, this will need to be corrected in Photoshop. All that is needed is a rearrangement of the custom channels. B - Loading a PDF, PS, or EPS Composite File PDF, PS, or EPS files rely on spot colors to define the regions where white ink will be printed. The name of the spot color is important. For ONYX to automatically assign a spot color to the spot ink channel, the name must be Spot1. If the media has multiple spot ink channels, the other names for your spot colors would be Spot2, Spot3, etc. Spot1 is assigned to the first spot ink channel listed in the media profile. Spot2 is assigned to the second spot ink channel, etc. Any issues dealing with spot colors being assigned incorrectly will need to be readdressed in the design application. All that is needed is to rename the affected spot colors so they will be auto-assigned correctly in ONYX. How does ONYX assign spot colors with different names to the media s spot ink channel? The first method involves telling ONYX which spot is assigned to a spot ink channel. In the color management settings in the Quick Set or in Preflight there is an option called Spot Channel Replacement. Under this option a spot color name can be set to map to a spot ink channel. To get there, either edit or create a Quick Set. Under the first window click the button Change Profiles from the Color Management section. Go to the Output tab. Finally, select the Spot Channel Replacement button. Image 10: Spot Channel Replacement 8

9 In the Spot Channel Replacement window, there are two sections. The bottom half, PostScript Spot Color to Ink Channel Replacement, controls what spot color is assigned to which spot ink channel. Under the first entry double-click on <None> and type in the spot color name. The name needs to match the spot color s name exactly. Once this is set, and the Quick Set is saved, any jobs loaded into ONYX will have that spot color automatically assigned to the profiles spot ink channel. This option is also available in Preflight, under the Printer and Media tab. Select Change Profiles. Finally, under the Output tab on the new window, the option will be seen. The Spot Channel Replacement option is available only for ProductionHouse. When using Postershop the options to do this are limited. The file will need to be taken back to the design application and the name of the spot color will need to be changed to Spot1. Another option would be to output the file as a separation PDF or PostScript. C - Loading a Separation File When a separation file comes into ONYX it is treated, by default, as a composite file. ONYX needs to be told how to reconstruct the separation file. This can be done either in a Quick Set or in Preflight. Create or edit a Quick Set. Select the Advanced button. All the separation options are listed under the PostScript File tab. Place a check mark next to the box Separation File. The options below will now be available. Under most conditions the only option that needs to be altered is the section Spot Separations. Change this value to the number of spot separations your file has. The Color Order and other options can be left as the default values. Image 11: Separation File Options Under most circumstances the option Color Order will not need to be changed. By default the Adobe separation files all start with the process separations first, then come the spot separations. The spot separations are listed in alphabetical order, based on the name of the spot color. So the first spot separation listed alphabetically will be assigned to the first spot ink channel. If the separation file was created from an unknown source, such as a customer s graphic designer, the order of separations can be verified by bringing the file into Adobe Acrobat Reader. Next to the page number you will see the name of the separation that page represents. This will also show the names of each spot separation. Image 12: Page name as seen in Acrobat If the first spot separation is assigned to the wrong spot ink channel, adjustments can be made in ONYX. In the PostScript File section, change the option Color Order from CMYK to Custom. Select the second spot separation, Spot2, and choose Move Up. The Spot2 will now come before Spot1. 9

10 Image 13: Reordering Spot Separations For example, a separation file with 2 spot separations, gloss and white, is rendered to a media with an ink configuration of CMYKWGl. Because Adobe orders the spot separations in alphabetical order, gloss will be rendered to the first spot ink channel and white to the second. So in this example, the gloss separation will be assigned to the white spot ink channel and the white to the gloss. In order to resolve this set the Color Order to Custom. Now select Spot2 at position 6 and then select the Move Up button. Spot2 will now be placed in position 5. This will assign the second spot separation, white, to the white spot ink channel and the gloss to the gloss spot ink channel. This can be set up in the Quick Set or in Preflight. D - Some Additional Points If the image has PANTONE or other spot colors, in addition to white data, it is recommended to use a standard composite file. It is possible to use a mixture of spot colors, like PANTONE or RAL, and spot white data in a separation file. However, the steps to do this can be complicated depending on the image. This will not be discussed in this document. As it was stated earlier, separation files have a limit of 12 separations. It is possible to verify the white ink data before printing. To do this bring the image into Preflight. The color used in ONYX to represent the spot ink channel should be present. To confirm this select the Color Correction tab. Select Tools and choose Sample Point. As the mouse hovers over the area, it will display the CMYK+ spot ink data that will be printed. One problem may still hinder the printing of white ink data. The Quick Set options, Two Stage Processing and Antialiasing, will prevent the white ink data from printing. It will still show it correctly in Preflight. Verify in the Quick Set that neither of these options is enabled. These options can be found under the Advanced section of the Quick Set in the PostScript tab. They are also accessible on a job to job basis in Preflight, under File > Job Properties in the PostScript tab. IV. Troubleshooting If you run into problems with the white ink not being detected correctly by ONYX, please see our troubleshooting document, available online. ONYX Graphics Inc S. High Tech Drive Salt Lake City, UT Phone: Toll Free: ONYX, the ONYX logo, ONYX PosterColor and ONYX PosterShop are registered trademarks, and ONYX ProductionHouse, ONYX RIPCenter and ONYX GamaPrint are trademarks of ONYX Graphics, Inc. All product and company names are trademarks or registered trademarks and are the property of their owners and are respectfully acknowledged. Copyright 2010, ONYX Graphics, Inc. All rights reserved. 10