Introduction

Just a 10-minute hack to explore putting spot colours into a PDF via pdf_colorstack nodes. I don’t have access to Acrobat Professional at the moment to check the separations properly, so treat this as an “alpha” method (i.e., not fully tested…). The colour defined below is lifted straight from an early PDF specification and implemented via LuaTeX nodes. As it says “on the tin”: a quick and dirty method :-).

\pdfoutput=1
\hoffset-1in
\voffset-1in
\nopagenumbers
\pdfcompresslevel=0

\directlua {

n = pdf.immediateobj("stream", "{ dup 0.84 mul
exch 0.00 exch dup 0.44 mul
exch 0.21 mul
}", "/FunctionType 4
/Domain [0.0 1.0]
/Range [0.0 1.0 0.0 1.0 0.0 1.0 0.0 1.0] ")

o = pdf.immediateobj("[ /Separation
/LogoGreen
/DeviceCMYK".." "..n.." 0 R]")

pdf.pageresources =  " /ColorSpace << /LogoGreen "..o.." 0 R >> "

pdf_colstart = node.new("whatsit","pdf_colorstack")
pdf_end = node.new("whatsit","pdf_colorstack")

pdf_colstart.data="/LogoGreen  CS  /LogoGreen cs 1  SC  1 sc "
pdf_colstart.cmd=1

pdf_end.data= " "
pdf_end.cmd = 2

tex.box[1999]= node.hpack(pdf_colstart) 
tex.box[2000]= node.hpack(pdf_end) 

}

\def\makeitgreen#1{\copy1999\relax#1\copy2000\relax}

There are many variations of passages of Lorem Ipsum available, but the majority have suffered alteration in some form, by injected humour, or randomised words which don't look even slightly believable. If you are going to use a passage of Lorem Ipsum, you need to be sure there isn't anything \makeitgreen{embarrassing hidden in the middle of text. All the Lorem Ipsum generators on the Internet tend to}  repeat predefined chunks as necessary, making this the first true generator on the Internet. It uses a dictionary of over 200 Latin words, combined with a handful of model sentence structures, to generate Lorem Ipsum which looks reasonable. The generated Lorem Ipsum is therefore always free from repetition, injected humour, or non-characteristic words etc.

\bye

Resulting PDF

As usual, through the Google Docs viewer or download here.