pagebreak, newpage don't work with textblock, textpos

Question

I use textpost, textblock to put two tcbpost in one page: 2 tcbposter in one page and set absolute position

But \pagebreak, \newpage don't work when I insert another posterbox (BOX C).

Please help; don't remove textblock.

Minimal code:

\documentclass[12pt]{article}
\usepackage[a4paper]{geometry}
\usepackage[poster]{tcolorbox}
\usepackage[absolute%,showboxes
]{textpos}
\setlength{\TPHorizModule}{1cm}
\setlength{\TPVertModule}{1cm}

\pagestyle{empty}
\begin{document}
\begin{textblock}{6}(1,2)
\begin{tcbposter}[
coverage = {left=0pt,right=0pt,top=0pt,bottom=0pt},
  poster = {
    columns=1,
    rows=2,
    spacing=3mm,
    height=14cm,
    width=6cm,
  },
  ]
  \posterbox[
  colframe = red,
  width=5cm, height= 10cm
  ]{ }{\includegraphics[width=3cm]{example-image-a}}

\end{tcbposter}

\end{textblock}

\begin{textblock}{6}(7,5)
\begin{tcbposter}[
coverage = {left=0pt,right=0pt,top=0pt,bottom=0pt},
  poster = {
    columns=1,
    rows=2,
    spacing=3mm,
    height=14cm,
    width=6cm,
  },
  ]
  \posterbox[
  colframe = blue,
  width=5cm, height= 10cm
  ]{ }{\includegraphics[width=3cm]{example-image-b}}

\end{tcbposter}
\end{textblock}
%%%BOX C
    \clearpage
\pagebreak
\newpage

\begin{textblock}{6}(2,5)
\begin{tcbposter}[
coverage = {left=0pt,right=0pt,top=0pt,bottom=0pt},
  poster = {
    columns=1,
    rows=2,
    spacing=3mm,
    height=14cm,
    width=6cm,
  },
  ]
  \posterbox[
  colframe = yellow,
  width=5cm, height= 10cm
  ]{ }{\includegraphics[width=3cm]{example-image-c}}

\end{tcbposter}
\end{textblock}

\end{document}

Answer 1

You can only use \newpage when there is already content on the page, but \textblock does not add content to the page (it rather puts something on top of the page). To cure this, add something invisible like ~ before the \newpage.

\documentclass[12pt]{article}
\usepackage[a4paper]{geometry}
\usepackage[poster]{tcolorbox}
\usepackage[absolute%,showboxes
]{textpos}
\setlength{\TPHorizModule}{1cm}
\setlength{\TPVertModule}{1cm}

\pagestyle{empty}
\begin{document}
\begin{textblock}{6}(1,2)
\begin{tcbposter}[
coverage = {left=0pt,right=0pt,top=0pt,bottom=0pt},
  poster = {
    columns=1,
    rows=2,
    spacing=3mm,
    height=14cm,
    width=6cm,
  },
  ]
  \posterbox[
  colframe = red,
  width=5cm, height= 10cm
  ]{ }{\includegraphics[width=3cm]{example-image-a}}

\end{tcbposter}

\end{textblock}

\begin{textblock}{6}(7,5)
\begin{tcbposter}[
coverage = {left=0pt,right=0pt,top=0pt,bottom=0pt},
  poster = {
    columns=1,
    rows=2,
    spacing=3mm,
    height=14cm,
    width=6cm,
  },
  ]
  \posterbox[
  colframe = blue,
  width=5cm, height= 10cm
  ]{ }{\includegraphics[width=3cm]{example-image-b}}

\end{tcbposter}
\end{textblock}

~\newpage

\begin{textblock}{6}(2,5)
\begin{tcbposter}[
coverage = {left=0pt,right=0pt,top=0pt,bottom=0pt},
  poster = {
    columns=1,
    rows=2,
    spacing=3mm,
    height=14cm,
    width=6cm,
  },
  ]
  \posterbox[
  colframe = yellow,
  width=5cm, height= 10cm
  ]{ }{\includegraphics[width=3cm]{example-image-c}}

\end{tcbposter}
\end{textblock}

\end{document}