Thank's Martin for posting this Link! I've been using it lately in my press calibrations and it yielded results that are quite comparable to IDEALinkCurve, sometimes to the fraction of a decimals. Are you using it yourself? Best / Roger > The Heidelberg procedure: > > http://www.heidelberg.com/wwwbinaries/bin/files/dotcom/en/prinect/prine > ct_user_guide_grey_balance_en.pdf > > Martin Weberg