Transparency and how to make it work

Production Tips & Tricks 

effectsThe effects that transparency tools can create in InDesign, Illustrator, and Quark are great for designers who wish to give their graphics that extra edge. While the feathering, gradients, drop shadows, etc. make the design look great on the screen, a document containing these effects may be an obstacle for your printing service provider to overcome if the file is not set up correctly. This can be caused by several situations; sometimes the PostScript RIPs (Raster Image Processors) used by your printer may not be capable of processing the transparency and therefore cause the dilemma, or it can be from selecting spot colors instead of process. To avoid complications and unexpected printing results, there are measures that can be taken.

For designs with process colors

If you are designing a piece that will print in process colors (cyan, magenta, yellow, black) you can use transparency without any issues. The only problem we encounter is when designers use spot colors. If your document contains spot colors as opposed to process colors, you may get unexpected results when applying blending modes or other effects such as drop shadows. Blending modes control how the underlying color will perform with the blend color and includes such settings as Multiply, Screen, Overlay etc.

Make sure that if you have selected a Pantone or spot Color that you convert them over to process color. While the document is open in InDesign, spot colors will appear to look fine on the screen when combined with a transparency and may even look correct when the PDF is viewed on screen. But this is not necessarily how the document will look when printed. If you use spot colors, when the file is flattened the areas of spot color with transparency are rasterized and this can create a color shift (see previous article “Why is a PMS color different from its 4-color build?”). Using process colors when designing with transparencies is the sure way of getting the desired effect in your final print.

For designs with Spot Colors

You can use spot colors and transparency effects, you just have to trick the program into doing what you want it to. For a job that uses spot colors with no process colors, if you assign spot colors to process colors you will be fine. Let us explain that. If you are printing a job that is 2-colors, black and PMS 280, you would actually design it as black and cyan. These are two process colors so transparency will work without any problems. When we process your file we will map the cyan to PMS 280.

But how do you do proofs? This can create a new set of problems if you use a digital printer for proofs. Here is our workaround, first choose color PMS 280 and place it in your Color Palette. Then go edit the color and change PMS 280 to a process color and then change the name to 280. Make sure you remove the word Pantone or PMS. You can now build your file and do all of your proofs and your 280 color will look like PMS 280. Then before you send us your file or create your PDF, edit the CMYK build of your 280 color to be 100% Cyan only. The colors in your document will now be black and cyan. You can use this technique for up to 4 spot colors in one design, if you have more than four spot colors you should probably call us to discuss the best options.

For designs with 5-colors

If you are creating a job that prints in 5-colors and is using transparency, please let your salesperson or CSR know before you get too far in the design process. We have some suggestions for you to make sure it all works correctly, but they tend to be on a per job basis. It will be much harder to fix the files after you are finished.

How Flattening works

To address any issues that the RIPs may encounter, the process of flattening has become a useful tool when designing with transparencies.  Flattening works by dividing the transparent graphics into smaller non-transparent objects, which can be supported by the RIPs. To achieve flattening in InDesign, there are presets, which can be chosen before beginning your design and also when you make the PDF. These presets can be found in Transparency Flattener Presets under the Edit tab. Here you will find presets for low, medium and high-resolution and you also have the option to create your own.

After choosing your preset, InDesign will then automatically flatten the transparencies you create according to the settings chosen. If you are printing you must use the High-Resolution setting, otherwise the flattened areas will be low resolution and will not print correctly.

transparencyAs an example, let’s say that the design includes a 60 percent transparent cyan square on top of a yellow and magenta square. After flattening, there will be a total of four objects. Where the color boxes overlap, two rasterized rectangles are created using cyan and yellow (2) and cyan and magenta (1). So after rasterizing, we will have two raster images (indicated by the 1 & 2) and then the solid vector colors of yellow and magenta around the outside edges.

If InDesign recognizes that flattening will take too long, creating a file that will take a long time to print, it will just turn the entire file into a rasterized bitmap image. In most cases this won’t be a problem, however if your document contains small text or fine line graphics, this may create an undesirable softening effect or make some fine details appear jagged.

When used appropriately, flattening presets can easily give you the desired final product. Note that transparency content is only editable in the original application from which it was created. That being said, it is always a good idea to send along the original file with all of its elements with your PDF to your printer. We recommend using the “Package” function in InDesign or the “Collect for Output” in Quark to collect and package for files to send to us. We have instructions for this on our web site. This gives us the ability to make adjustments if we run into complications while preparing your files.


One aspect of flattening is that it can create artifacts. They appear as very thin white lines in your PDF file. You will know they are artifacts because if you zoom in on them, they never get any wider. They show the outline of the objects that have been flattened. 99% of the time these lines will not show up once the file is printed. However, your client may see them in proofing PDFs and ask, and no there is no way to make them go away.

To avoid common transparency printing mistakes, we advise designers to stick with CMYK. Make sure your Transparency Flattening Presets are set to High Resolution and always preview your PDFs before sending them to us. Remember, clear communication with your printer will lead to the results you expect.

About Printing Partners

Commercial & digital printing, graphic design, direct mail, mailing services, promotional products all located under one name, Printing Partners - Indianapolis, Indiana. Printing Partners is FSC Certified and is a G7 Master Printer.
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One Response to Transparency and how to make it work

  1. Pingback: Please don’t build your files in printer spreads « Connecting the Dots

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