% PDF/X-1a
\pdfminorversion=3
\pdfobjcompresslevel=0
\setupcolors[rgb=no]% only CMYK and Gray allowed


%\embedICCprofile{CMYK}{ISOcoated_v2_300_eci.icc}

\usePDFXoutputintent
  [%reference=no,
   info={ISO Coated v2 (ECI)},
   outputcondition={Offset printing, according to ISO 12647-2:2004/Amd 1, OFCOM, paper type 1 or 2 = coated art, 115 g/m2, tone value increase curves A (CMY) and B (K)},
   id=FOGRA39,
   name=http://www.color.org]


\starttext

\setupinteraction
  [title=TITLE,
   subtitle=SUBTITLE,
   author=AUTHOR,
   keyword={{KEYWORD1, KEYWORD2}, KEYWORD3},
  ]


\startluacode
-- PDF/X-1a:2003
lpdf.addtoinfo("GTS_PDFXVersion","PDF/X-1a:2003")
lpdf.injectxmpinfo("xml://rdf:RDF","<rdf:Description rdf:about='' xmlns:pdfxid='http://www.npes.org/pdfx/ns/id/'><pdfxid:GTS_PDFXVersion>PDF/X-1a:2003</pdfxid:GTS_PDFXVersion></rdf:Description>",false)
\stopluacode
\null

\definecolor[cmykblack][k=1]

\hbox\bgroup
\blackrule[color=cyan,width=1cm,height=1cm]%
\blackrule[color=magenta,width=1cm,height=1cm]%
\blackrule[color=yellow,width=1cm,height=1cm]%
\blackrule[color=cmykblack,width=1cm,height=1cm]
\egroup

\stoptext