A Guide to using White ink in your designs The use of white ink is a great way to enhance your design and print solution. White ink gives you the option to print on alternative materials such as metallic, plastic or dark stocks, either on its own or as an undercoat in combination with four colour process. Applying techniques such as knock out in combination with the white ink can create an stunning results. HOW TO SET UP A White channel Select any spot colour and re-name the 01 swatch White, making sure the W is capitalised. TIP: Try to use something noticeable such as magenta, to help avoid confusion with other more prominent colours in your artwork (see fig 1.1). fig 1.1 Make sure the Colour Type is set to Spot Anything set up with the White swatch will print using white ink. So, if you want text to print white you need to assign your text as the White swatch. The same concept applies for strokes, drop shadows and fills etc. The areas of White will appear in your document as the spot colour you originally chose. This may seem confusing, but these areas will print using white ink (see fig 1.2). fig 1.2 Note: For fully opaque white, the channel must be set to 100% opacity with no tints, effects or overprints. Different effects can be created by experimenting with these settings but for solid white, stick to 100% opacity. How your file will look on screen... How it would print... (on black paper) 1
Overprinting on White If you are using a paper stock, for 02 example silver mirror board, and don t want some areas to blend with this effect (i.e. the colours looking slightly metallic) then you can use a white channel beneath these areas to prevent this. Colours you want printed on top of white ink must be set to Overprint (see fig 2.1). If Overprint is not selected then the overlaying object will by default knock out the white ink channel beneath it (see fig 2.3), thus resulting in your object blending with the chosen paper stock. To apply an overprint: fig 2.1 The blue type has been set to Overprint Fill. (See fig 2.2) You can visually see the Overprint layer and the White layer merge by turning on the Separation Preview. (See fig 2.3) Illustrator: Window>Attributes>tick Overprint Fill/Overprint Stroke box. InDesign: Window>Attributes>tick Overprint Fill/Overprint Stroke box. Quark: Window>Trap Information> Background and move from Default to Overprint. fig 2.2 Make sure Overprint Fill is ticked. Note: There is a difference between Overprint Fill and Overprint Stroke. Overprint Stroke will need to be applied on any object or text with a stroke that is intended to be printed over an area of white. Applying a small allowance around an overprinted object or text will ensure any small alignment issues are compensated for. Usually a 0.1 pt stroke will be sufficient (see fig 3.2). fig 2.3 With Overprint fill turned on... Use the Output Preview feature in Acrobat Pro to check if you have set overprints correctly: Acrobat Pro: Tools>Print Production> Output Preview You can also use the Separations Preview window in Illustrator and InDesign: Illustrator: Window>Separations Preview InDesign: Window>Output>Separations Preview Once in Separations Preview you can check the ink levels applied to a page by hovering the cursor over the content (see fig 2.3). With Overprint fill turned off... (resulting in the four colour knocking out the White ) 2
fig 2.4 TIP: A useful technique for viewing the white areas is to turn off all colours except White in Output Preview and you will then see all the areas displayed as black in turn these will be printed white. Turning off the CMYK is a quick way to view areas of White in your document. If you are printing CMYK over an area of white then the White channel must display a value of 100% (See fig 2.4). If you turn the opacity to 99% or below, gradually, the colour and/or texture of the paper stock will start to blend in with your design. If used well this can create some interesting results! How the White channel displays on screen with CMYK turned off. Undercoats of White 03 You may want to overprint images that are more complicated than just lines and text. To do this you will need to duplicate your image and convert it into one block or silhouette of White which then sits behind your original image as an undercoat. fig 3.1 With square or circular images this is straight forward but with more detailed images it can take a bit more work to replicate the shape. You will either need to copy the original object and Unite the elements with the Pathfinder tool (Illustrator & InDesign) to make it a single object, or manually trace around the object with the Pen Tool (Illustrator, InDesign & Quark) to make your silhouette. There are many ways to achieve this result, all are acceptable as long as the final silhouette is accurate to the original shape and set up with the White swatch. Like in fig 2.1 you can see the layers merging in the same way. Consider an allowance of about 0.1 pt for any small alignment issues. The easiest way to do this is to offset -0.1 pt from the size of the undercoat. This can be done by the Offset Path option found in Illustrator. Alternatively, you can expand the object on top by +0.1 pt to create this (see fig 3.3). With text you simply just have to duplicate the text box, set the text with the White swatch and place it behind your original text. Again, subtracting fig 3.2 a stroke of 0.1 pt and don t forget to select the Overprint Stroke. 3 fig 3.3
NOTE: 0.1 pt is an estimate given in this tutorial. If you have an image with a lot of fine detail then it may be worth increasing this allowance accordingly. Photographs and images 04 For any photographs or images you want printed over an area of white will need to be set to Multiply (see fig 4.1). This is a similar setting to overprint and stops the image knocking out the white ink beneath. To apply Multiply : Illustrator: Window>Transparency>Select Multiply from the drop down menu. InDesign: Window>Effects>Select Multiply from the drop down menu. Providing that you have Overprint Fill selected for the picture attributes, you should be able to see the White channel (whatever spot channel you selected) through the image. This usually results in the two images looking rather odd (similar to fig 4.2), but you will need to trust that the image will print out with white ink under your chosen image (see the bottom reference of fig 4.2). fig 4.1 fig 4.2 How your file will look on screen... When overprinting images the Blending mode will need to change to Multiply. How it would print... (on black paper) Stacking and ORDER of LAYERS 05 The stacking order is important in setting up a white ink channel properly. All overprinted objects must be stacked on top of the White channel (see fig 5.1). How to change the stacking order: Illustrator: Object>Arrange>Bring To Front InDesign: Object>Arrange>Bring To Front Quark: Item>Bring To Front Output Preview doesn t allow you to check for the stacking order, so you ll need to go back to your editable Illustrator, InDesign or Quark document and manually check this (see fig 5.1). Layers with a White channel need to be underneath (see fig 5.2). fig 5.1 fig 5.2 4
Summary 06 fig 6.1 Use the checklist below to ensure all items are covered. If you are viewing this PDF in Acrobat Pro you can look at fig 6.1 through the Output Preview to see how a finalised piece of artwork should be set up. Try toggling between the White channel and the CMYK channels. How to view Output Preview : Acrobat Pro: Tools>Print Production> Output Preview Checklist: Have you set the white channel as a spot colour and re-named it White (with a capital W)? Have you set the White channel to 100% opacity with no effects, tints or overprint attributes applied (unless other effects are desired)? Have you set any objects or text that you intend to print on top of areas of white to Overprint Fill and/or Overprint Stroke? Have you set any images/photographs that you intend to print on top of areas of white to Multiply? Are all overprinted items on-top of the stacking order? Have you checked any areas intended to overprint onto White display both the CMYK ink values as well as the ink value for the White channel (see top example of fig 2.3). An example of finished artwork printed onto gold card! TIP: Use of White Ink on metallic stocks. If you were using a large undercoat of white on a metallic stock and deselected Overprint Fill (see fig 2.2) on an object or block of text you would then knock out all ink levels underneath. This in turn would knock out the CMYK values and the White channel right down to the paper, leaving the metallic paper stock to show through. Setting your object or text swatch to (0%/0%/0%/0%) or [Paper] will mean a 100% opaque knock out occurs leaving nothing but the paper showing through, which is a perfect alternative to foil blocking! 5