title: Convert PDF to CMYK but ignore black?
body: <p>I am converting an RGB PDF to CMYK using the following command:</p>
  
  <pre><code>/usr/local/bin/gs -dSAFER -dBATCH -dNOPAUSE -dNOCACHE -sDEVICE=pdfwrite \ 
  -sColorConversionStrategy=CMYK -sColorConversionStrategyForImages=CMYK \
  -dProcessColorModel=/DeviceCMYK -dEncodeColorImages=false \
  -dEncodeGrayImages=false -dEncodeMonoImages=false -sOutputFile=CMYK.PDF RGB.PDF
  </code></pre>
  
  <p>The resulting file is 100% CMYK, however anything that was 100% black in the RGB PDF is now:</p>
  
  <pre><code>C: 72%
  M: 68%
  Y: 67%
  K: 89%
  </code></pre>
  
  <p>The result is that black is a slightly dark grey when really it should be black.</p>
  
  <p>Is there anything I need to add to this command to ensure black remains as black during the conversion?</p>