# Put text anywhere at the document

I am wondering whether it is possible to position any object like text or image on top or behind the existing text in the document without affecting it?

That is to say, make an object float like a new layer in image editor.

A small tikz example:

with this piece of code:

\documentclass[a4paper]{article}

\usepackage{lipsum}
\usepackage{tikz}
\usetikzlibrary{calc}

\begin{document}

\begin{tikzpicture}[remember picture, overlay]
\draw[blue, fill=blue!20, fill opacity=0.7]
(current page.center) circle (3cm)
node {Blue circle behind text};
\end{tikzpicture}

\lipsum[3]

\lipsum[9]

\begin{tikzpicture}[remember picture, overlay]
\draw[red, fill=red!20, fill opacity=0.7]
($(current page.north)+(0,-4)$) circle (3cm)
node {Red circle in front of text};
\end{tikzpicture}

\end{document}