Web to print colour mapping

Print templates are created using RGB colours since they are created and managed through the browser.

In order to ensure the correct CMYK colours are output when templates are converted to PDF a mapping needs to be created between the RGB colour in the template and the required CMYK colour in the final PDF.

When creating templates please provide Vuture with the required colour mapping from web colour (Hex or RGB) to print colour (CMYK) to  so they can be added to your system, e.g.:

Light Blue

HEX - #00ABCD or RBG - 0 171 205 

CYMK - 84 0 18 0

  

Dark Blue

HEX - #002F43 or RBG - 0 47 67

CYMK - 100 30 19 76

Guide for Vuture technical team to setup new colour mappings

1. Create a simple test page

 e.g. if the web colour is #00ABCD

<!DOCTYPE html>
<html>
<head>
<title>Print test</title>
</head>
<body>
<div style="position:absolute;width:10cm;height:10cm;background-color:#00ABCD;color:#00ABCD">
    <!-- empty -->
</div>
</body>
</html>

 

2. Generate this page as a PDF and find the incorrect colour

• Load this page into a Vx print template, and generate this page as a PDF.  
  
• Run the PDF generator in debug mode, with a breakpoint in `private Doc _tweakColours() { ... }` and grab the `doc.GetText("SVG+")` result.  Search for an attribute called `pdf_Op` with a value ending in ‘SCN’ or ‘scn’. e.g., ‘0.75392 0.51064 0.40072 0.61779 scn’. This value should be similar to the expected output.  Reduce each colour segment to two decimal points plus '[0-9]+' and add into the `Dictionary<Regex, string> ColourConversion` dictionary with a the regex you created and the CMYK values where 100% = 1 and 66.6% = 0.666.  
  

3. Test the colour swap

Re-generate the PDF and run through Acrobat’s preflight to ensure the conversion is correct by opening the PDF in Adobe Acrobat Pro and clicking on "Edit", "Preflight"

Under the PDF Analysis section select "List page objects, grouped by type of object" then click "Analyze"

This will show the CMYK colours for the converted blocks of colour which you can verify are correct.

Once the colour mapping has been checked-in to production it is available to all instances.