Converting to CMYK in Pitstop
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Johnathan T
- Newbie
- Posts: 3
- Joined: Fri Sep 22, 2023 7:05 pm
Converting to CMYK in Pitstop
We have always let our Fierys handle colour conversion but we are looking into options to handle that elsewhere to get more consistent colour across our presses using pitstop server and switch. Primarily our customers supply RGB files. Currently, when we convert to CMYK we always get a significant change in colour, which is expected. However, we know there is a way to do this properly we just don’t know how to do it. If anyone has any information or resources so we can learn more about colour management it would be greatly appreciated.
Re: Converting to CMYK in Pitstop
Go to this page https://www0.enfocus.com/en/learn/pitstop/all and search for "color management".
What you basically have to do is make sure that the correct input and output profiles are defined in your color management settings at the moment you perform the color conversion, be it interactively in Pro or via a profile or action list in Pro and/or Server.
What you basically have to do is make sure that the correct input and output profiles are defined in your color management settings at the moment you perform the color conversion, be it interactively in Pro or via a profile or action list in Pro and/or Server.
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magnussandstrom
- Advanced member
- Posts: 535
- Joined: Thu Jul 30, 2020 6:34 pm
- Location: Sweden
- Contact:
Re: Converting to CMYK in Pitstop
Hi Jonathan,
This will be a slightly long explanation, but I hope it helps clarify how we work and *why* we’ve chosen this approach.
We operate three different print shops and produce jobs using several printing technologies, such as sheetfed digital presses, large-format inkjet printers, and offset presses. Because of this variety, consistency is very important for us.
Overall idea – one common color starting point
Our main goal is to make sure that all incoming files are treated in a predictable and consistent way, regardless of where they come from or where they will be printed. To achieve this, we “normalize” all files in Enfocus Switch before they go to our RIPs or DFEs.
Think of this as bringing everything into a common color language before RIPs or DFEs.
---
How we handle different color types:
RGB content
All RGB objects in incoming files are converted to our internal “house CMYK” profile (we use Fogra51).
* We respect embedded RGB profiles if they exist
* If no RGB profile is embedded, we assume **sRGB**
* Conversion is made using *relative colorimetric with black point compensation*
---
CMYK objects with embedded profiles
In most cases, we remove embedded CMYK profiles from incoming files and treat all CMYK data as our house CMYK.
This might sound controversial, but it has significantly reduced mistakes and customer complaints for us. In the past, mixed CMYK profiles inside the same PDF (for example images and vector objects tagged differently) caused unpredictable results.
That said, we do use common sense:
* If a customer delivers a high-end job (for example a photobook) clearly intended for a specific CMYK standard like SWOP, we will contact them
* In special cases, we respect the embedded CMYK profile
---
PDF Output Intent profile
We remove the Output Intent profile from incoming PDFs and replace it with our "house CMYK".
In practice, the Output Intent usually only reflects the customer’s CMYK working space in their layout software. Since we already control color centrally, we don’t rely on that information.
---
Unwanted spot colors
Unwanted spot colors are converted automatically:
* We match the spot color name to Pantone v4 Lab values using Pitstop
* Those Lab values are then converted to *house CMYK* using relative colorimetric with black point compensation
* If the spot color name is not found, we convert it using the alternate color space already present in the PDF
This gives us predictable and consistent CMYK results when spot colors are not meant to be printed as actual spot inks. We do restrict the gamut to "house CMYK", but we do not see that as an issue in most scenarios.
---
Automated workflow in Enfocus Switch
Our Switch flow applies the following rules automatically (in this order):
1. Preflight checks
* Verify image resolution
* Check fonts
* Knock out white objects set to overprint
2. Color conversion
* Convert all RGB content to house CMYK
* Convert unwanted spot colors to house CMYK
3. PDF/X validation
* If the file *is* valid PDF/X → impose and send to RIP/DFE
4. Transparency handling (if not PDF/X)
* If transparency exists → flatten transparency, then impose and send to RIP/DFE
* If no transparency exists → impose and send to RIP/DFE without further changes
This way everything is CMYK and based on the same reference before RIP/DFE. Later, inside the RIP or DFE, CMYK colors are converted for the specific press and paper, using in RIP color management (CMYK-to-CMYK or curves). This two-step process helps us get consistent results across different presses and materials.
---
In short:
We standardize everything early in the workflow (before any soft proofs or hard proofs), so the RIP only needs to focus on adapting one known CMYK source to the final output device. This has helped us reduce errors, improve consistency, and simplify troubleshooting across multiple printing technologies.
Hope this explanation is useful.
Feel free to ask any follow-up questions if there’s anything you’d like clarified or if you want more details about how we set this up in Switch.
This will be a slightly long explanation, but I hope it helps clarify how we work and *why* we’ve chosen this approach.
We operate three different print shops and produce jobs using several printing technologies, such as sheetfed digital presses, large-format inkjet printers, and offset presses. Because of this variety, consistency is very important for us.
Overall idea – one common color starting point
Our main goal is to make sure that all incoming files are treated in a predictable and consistent way, regardless of where they come from or where they will be printed. To achieve this, we “normalize” all files in Enfocus Switch before they go to our RIPs or DFEs.
Think of this as bringing everything into a common color language before RIPs or DFEs.
---
How we handle different color types:
RGB content
All RGB objects in incoming files are converted to our internal “house CMYK” profile (we use Fogra51).
* We respect embedded RGB profiles if they exist
* If no RGB profile is embedded, we assume **sRGB**
* Conversion is made using *relative colorimetric with black point compensation*
---
CMYK objects with embedded profiles
In most cases, we remove embedded CMYK profiles from incoming files and treat all CMYK data as our house CMYK.
This might sound controversial, but it has significantly reduced mistakes and customer complaints for us. In the past, mixed CMYK profiles inside the same PDF (for example images and vector objects tagged differently) caused unpredictable results.
That said, we do use common sense:
* If a customer delivers a high-end job (for example a photobook) clearly intended for a specific CMYK standard like SWOP, we will contact them
* In special cases, we respect the embedded CMYK profile
---
PDF Output Intent profile
We remove the Output Intent profile from incoming PDFs and replace it with our "house CMYK".
In practice, the Output Intent usually only reflects the customer’s CMYK working space in their layout software. Since we already control color centrally, we don’t rely on that information.
---
Unwanted spot colors
Unwanted spot colors are converted automatically:
* We match the spot color name to Pantone v4 Lab values using Pitstop
* Those Lab values are then converted to *house CMYK* using relative colorimetric with black point compensation
* If the spot color name is not found, we convert it using the alternate color space already present in the PDF
This gives us predictable and consistent CMYK results when spot colors are not meant to be printed as actual spot inks. We do restrict the gamut to "house CMYK", but we do not see that as an issue in most scenarios.
---
Automated workflow in Enfocus Switch
Our Switch flow applies the following rules automatically (in this order):
1. Preflight checks
* Verify image resolution
* Check fonts
* Knock out white objects set to overprint
2. Color conversion
* Convert all RGB content to house CMYK
* Convert unwanted spot colors to house CMYK
3. PDF/X validation
* If the file *is* valid PDF/X → impose and send to RIP/DFE
4. Transparency handling (if not PDF/X)
* If transparency exists → flatten transparency, then impose and send to RIP/DFE
* If no transparency exists → impose and send to RIP/DFE without further changes
This way everything is CMYK and based on the same reference before RIP/DFE. Later, inside the RIP or DFE, CMYK colors are converted for the specific press and paper, using in RIP color management (CMYK-to-CMYK or curves). This two-step process helps us get consistent results across different presses and materials.
---
In short:
We standardize everything early in the workflow (before any soft proofs or hard proofs), so the RIP only needs to focus on adapting one known CMYK source to the final output device. This has helped us reduce errors, improve consistency, and simplify troubleshooting across multiple printing technologies.
Hope this explanation is useful.
Feel free to ask any follow-up questions if there’s anything you’d like clarified or if you want more details about how we set this up in Switch.