# Rotating text in marginnote?

I am creating a one-page conference flyer featuring a background image. I would like to add a photo credit positioned to the lower right corner of the page, but rotated 90 degrees. How to do this nicely?

I am using eco-pic to have the background image, as described here: How to create a background image on title page with LaTeX?

Then I tried this Text that is centered horizontally but absolutely placed vertically to position a text absolutely.

However, this method failed, as the text was hidden under the background image, and it was not visible (but only searchable).

I also tried to put the text to the footer, but a) I was unable to push the text to the right side of the page; and b) once rotated (with \usepackage{rotating}) the text was unable to run above the bottom margin.

So it seems to me that this could be done by a well-positioned margin note, by using \marginpar or \marginnote. But then, rotating the text will not position it to the right side of the page, but rather at a distance of \rightmargin.

I am also using the contour package (to outline the text so that it is more readable), which is -- if I understand correctly -- creates an mbox-like environment, so I would rather not have any linebreaks in the solution. I just want to write starting from the lower right corner, 90 degrees upwards.

Seems like a lot of effort for the one irrelevant information on the flyer.

Here's an option in which I used the background package to position the sideways text:

\documentclass{article}
\usepackage[a6paper]{geometry}% just for the example
\usepackage{background}
\usepackage{eso-pic}
\usepackage{contour}

\newcommand\BackgroundPic{%
\put(0,0){%
\parbox[b][\paperheight]{\paperwidth}{%
\vfill
\centering
\includegraphics[width=\paperwidth,height=\paperheight]{papiro}
\vfill
}}}

\backgroundsetup{
angle=90,
opacity=1,
scale=1,
color=red,
nodeanchor=south west,
position={current page.south east},
contents={\contour{green!70!black}{This is the text that will go sideways}},
%hshift=20pt,% to move the text vertically
%vshift=-10pt% to move the text horizontally
}

\pagestyle{empty}

\begin{document}