# Tikzposter - opacity of the blocks

I am trying to make the blocks in tikzposter class less opaque. I can't find a direct way to do it other than changing the cls, which seem fairly complicated. Any ideas?

\documentclass[11pt,a0paper]{tikzposter}
\begin{document}
\begin{columns}

\column{0.5}
\block{A test!}{ %% Normal block
asddd
}

\column{0.5}
%% how do I change the background opacity of the block here?
%% I assume i need to do a renewcommand on \block, but that seems
\block[opacity = 0.5]{A test!}{
asd
}

\end{columns}
\end{document}

• It would be helpful if you composed a fully compilable MWE including \documentclass and the appropriate packages that sets up the problem. While solving problems can be fun, setting them up is not. Then, those trying to help can simply cut and paste your MWE and get started on solving the problem. – Peter Grill Oct 21 '16 at 4:39
• added a small example, though don't think its of any use – xcorat Oct 21 '16 at 4:47

Ok, created a new block style with opacity parameter.

Simple rudimentary example:

\documentclass[11pt,a0paper]{tikzposter}

\defineblockstyle{Default1}{
titlewidthscale=1, bodywidthscale=1, titlecenter,
titleoffsetx=0pt, titleoffsety=0pt, bodyoffsetx=0pt, bodyoffsety=0pt,
bodyverticalshift=0pt, roundedcorners=30, linewidth=0.4cm,
titleinnersep=1cm, bodyinnersep=1cm
}{
\begin{scope}[line width=\blocklinewidth, rounded corners=\blockroundedcorners]
\ifBlockHasTitle %
\draw[color=blocktitlebgcolor, fill=blocktitlebgcolor] (blocktitle.south west) rectangle (blocktitle.north east);
\draw[color=blocktitlebgcolor, fill=blockbodybgcolor, opacity=0.5] (blockbody.south west) rectangle (blockbody.north east);
\else
\draw[color=blocktitlebgcolor, fill=blockbodybgcolor, opacity=0.5] (blockbody.south west) rectangle (blockbody.north east);
\fi
\end{scope}
}
\useblockstyle{Default1}

\begin{document}
\node[above right,opacity=0.5,inner sep=0pt,outer sep=0pt] at (bottomleft) {\includegraphics[width=\paperwidth,height=\paperheight]{frog.jpg}};

\begin{columns}

\column{0.5}
\block{A test!}{
asddd
\input{sensitivity}
}

\column{0.5}
\block{A test!}{
asd
}

\end{columns}

\end{document}