overprint / knockout

[u-fischer]

Think about it, from https://tex.stackexchange.com/a/681368/2388:

\DocumentMetadata{}
\documentclass{article}
\usepackage{iftex, transparent}

\ExplSyntaxOn
\pdfmanagement_add:nnn { Page / Resources / ExtGState } { no.text.knockout } { << /TK~false >> }
\ExplSyntaxOff

\ifpdftex
  \newcommand \disabletextknockout {%
    \pdfliteral page {/no.text.knockout gs}%
  }
\else
  \RequireLuaTeX
  \newcommand \disabletextknockout {%
    \pdfextension literal page {/no.text.knockout gs}%
  }
\fi
\begin{document}
\disabletextknockout
\vbox{%
  \hbox{\texttransparent{0.5}{hello}}%
  \vskip-\baselineskip
  \hbox{\texttransparent{0.5}{world}}%
}%
\end{document}