Work with color in pdfToolbox

Problems with incorrect color spaces and colors are a very frequent problem in graphic arts workflows and pdfToolbox offers a lot of functionality in this area to resolve such problems. Read on for an overview of what is supported (and what not)!

Preflight

First of all, of course pdfToolbox fully supports preflighting on color. In a preflight profile it’s possible to check on the use of RGB, spot color, calibrated color spaces (such as ICC-based color spaces), output intent used and much more. This gives you a complete solution to make sure the color you receive is actually what you want. The following sections will tell you what your options are if a document isn’t what you need.

Color conversion with ICC profiles

The most common color conversion is one with ICC profiles; given a source and destination ICC profile, the color engine converts all colors from source to destination. pdfToolbox Desktop has a dedicated Switchboard action for this type of color conversion.


Figure 1: process conversion tab in the Switchboard

This allows you to specify which type of file you are converting, what colors you want to convert (in the example everything will be converted with the exception of spot colors) and what your target is. This is a manual or interactive conversion and of course you can also perform this automatically.


Figure 2: fixup to convert all colors to ISOCoatedv2

The key here is the “Convert colors” fixup. This can be configured exactly to your liking and then included in a preflight profile. Such a preflight profile can be executed in all pdfToolbox products (Desktop, Server, CLI and SDK).

Color conversion using DeviceLink profiles

When converting from CMYK to CMYK or for special processing such as TAC reduction or ink saving, color conversion based on DeviceLink profiles gives better results and this too is possible in pdfToolbox.

Manually applying DeviceLink profiles

In pdfToolbox Desktop, the color group on the Switchboard contains the “DeviceLink conversion” item. Here you can select a DeviceLink profile to use, determine on which objects you want it to run and what color spaces you want to convert.


Figure 3: DeviceLink conversion using the Switchboard

Automatically applying DeviceLink profiles

Again using a fixup, the same technique is available in automated workflows.


Figure 4: TAC reduction using a fixup

The example fixup implements TAC reduction for PDF files using a ColorLogic profile.

Where to get DeviceLink profiles

pdfToolbox is only capable of applying DeviceLink profiles on PDF documents; it does not contain a profile editor or creator. To use the DeviceLink functionality, you will need DeviceLink profiles and there are a number of options in this regard:

  • You can use the DeviceLink profiles included in the DeviceLink option for pdfToolbox. This is a separate, payable, option that will provide you with a list of important DeviceLink profiles, mainly targeted towards converting between standards (such as between SWOP and ISOCoated)
  • You can use your own DeviceLink profiles. There are various tools such as CoPrA from ColorLogic that allow you to create DeviceLink profiles. What is important is to make sure that these profiles are open or unsecured so that they are usable in pdfToolbox.
  • You can purchase a DeviceLink pack created by another vendor. Such a pack contains premade DeviceLink profiles created by that vendor. A good example of such a vendor is ColorLogic which sells a wide range of DeviceLink packs that include the possibility to convert between standards, do TAC reduction or can be used in ink saving scenarios.

Working with spot colors

Changing or removing spot colors is another common question and pdfToolbox implements a wide range of functionality around spot color. In pdfToolbox Desktop you can interactively work with a list of spot colors in a PDF document.


Figure 5: working with spot colors in the Switchboard

For each spot color you have the possibility to change its name, alternate color space and values, remap it to a process color or other spot color or simply convert it to CMYK.

In an automated workflow you’re again better off using a fixup to remap spot colors or convert them to CMYK. The “Map spot and process colors” fixup makes it possible to remap spot colors or convert them to CMYK.


Figure 6: remapping spot color using a fixup

Fixing common color problems

In practice there are also a number of common color problems that don’t involve any of the previous color conversions. An example is correcting four color black which is shown in the example fixup below.


Figure 7: example fixup to convert 4C black to real black

pdfToolbox provides fixes for all common color problems, including:

  • Converting four color black to real black
  • Converting the color “All” (separation black) to real CMYK black
  • Converting rich black to real black or vice versa
  • Setting black or gray objects to overprint and white objects to knockout
  •  …

Which of these fixes are suitable for your workflow is a decision you need to make. But pdfToolbox does include all of this functionality to make it easy for you to correct whatever you feel you need to correct in PDF documents!

Questions?

You can read much more about all of the products mentioned in the product pages on the web site. Or simply contact us for a personalized demo or to ask more in-depth questions.