# Baposter: adjust transparency of body of context boxes

I am framing a poster using \baposter and making use of \definecolor{boxcolor} to select the background colour of the body of the content boxes. I am able to adjust the shade and colour of the boxes but am unable to make them translucent. How do I adjust the opacity of the boxes?

The original template which I'm making use of is given as follows:

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% NIWeek 2014 Poster by T. Reveyrand
% www.microwave.fr
% http://www.microwave.fr/LaTeX.html
% ---------------------------------------
%
% Original template created by:
% Brian Amberg (baposter@brian-amberg.de)
%
% http://www.LaTeXTemplates.com
%
%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

%----------------------------------------------------------------------------------------
%   PACKAGES AND OTHER DOCUMENT CONFIGURATIONS
%----------------------------------------------------------------------------------------

\documentclass[a0paper,portrait]{baposter}

\usepackage[font=small,labelfont=bf]{caption} % Required for specifying captions to tables and figures
\usepackage{booktabs} % Horizontal rules in tables
\usepackage{relsize} % Used for making text smaller in some places

\usepackage{amsmath,amsfonts,amssymb,amsthm} % Math packages
\usepackage{eqparbox}

\usepackage{textcomp}

\graphicspath{{figures/}} % Directory in which figures are stored

\definecolor{bordercol}{RGB}{40,40,40} % Border color of content boxes
\definecolor{headercol1}{RGB}{186,215,230} % Background color for the header in the content boxes (left side)
\definecolor{headercol2}{RGB}{120,120,120} % Background color for the header in the content boxes (right side)
\definecolor{headerfontcol}{RGB}{0,0,0} % Text color for the header text in the content boxes
\definecolor{boxcolor}{RGB}{210,235,250} % Background color for the content in the content boxes

\begin{document}

\background{ % Set the background to an image (background.pdf)
\begin{tikzpicture}[remember picture,overlay]
\draw (current page.north west)+(-2em,2em) node[anchor=north west]
{\includegraphics[height=1.1\textheight]{background}};
\end{tikzpicture}
}

\begin{poster}{
grid=false,
borderColor=bordercol, % Border color of content boxes
boxColorOne=boxcolor, % Background color for the content in the content boxes
headerfont=\Large\sf\bf, % Font modifiers for the text in the content box headers
textborder=rectangle,
background=user,
headerborder=open, % Change to closed for a line under the content box headers
}
{\includegraphics[scale=0.3]{CU.png}}
%
%----------------------------------------------------------------------------------------
%   TITLE AND AUTHOR NAME
%----------------------------------------------------------------------------------------
%
{ \bf  \huge {Large Signal Network Analyzer} \\  \Large \it An affordable PXI-based microwave non-linear characterization platform} % Poster title
{\vspace{0.3em} \smaller Tibault Reveyrand$^1$, Scott Schafer$^1$, John Boudreaux$^1$, Takao Inoue$^2$, Zoya Popovi\'c$^1$   \\  % Author names

\smaller $^1$\it {University of Colorado at Boulder} \\ $^2$\it{National Instruments} } % Author email addresses
{\includegraphics[scale=0.45]{NI.jpg}} % University/lab logo

%----------------------------------------------------------------------------------------
%   INTRODUCTION
%----------------------------------------------------------------------------------------
\begin{itemize}
\item The goal of this research is to integrate microwave-frequency Large Signal Network Analysis capabilities with commercially available National Instruments' PXI modular instrumentation and LabVIEW environment.
\vspace{-0.2cm}
\item The Microwave Research Group at the University of Colorado has decades of experience in UHF through millimeter-wave transmitters, including recent X-band (10-GHz) MMIC implementations in GaN. Our aim is to extend the frequency range and capabilities of available commercial instrumentation provided by NI.
\vspace{-0.2cm}
\item The proposed instrumentation development will enable new types of measurements such as those required for harmonically-terminated PAs, various transmitter architectures (Doherty, outphasing and supply modulated PAs), as well as microwave transistor rectifiers.  The time-domain characterization is expected to provide dramatic improvement in RF circuit design capabilities.
\end{itemize}
}

%----------------------------------------------------------------------------------------
%   CALIBRATION
%----------------------------------------------------------------------------------------
LSNA calibration algorithm consists of \textbf{3 steps} at each RF frequency: % \cite{verspecht2005large}
\begin{enumerate}
\item A relative VNA calibration creates an error-term matrix related to ports 1 and 2:
\begin{equation*}
\begin{pmatrix} a_ 1 \\  b_1 \\  a_2 \\ b_2 \end{pmatrix}=K\begin{bmatrix} 1 & \beta_1  & 0 & 0\\  \gamma_1 &  \delta_1  & 0 & 0 \\ 0 & 0 & \alpha_2 & \beta_2 \\ 0 & 0 &  \gamma_2 &  \delta_2 \end{bmatrix}.\begin{pmatrix} r_ 1 \\  r_2 \\  r_3 \\ r_4 \end{pmatrix}
\label{eq:cal_2_ports}
\end{equation*}

\item The power calibration gives $|K|$
\item The phase calibration yields $\arg\{K\}$
\end{enumerate}

Power and phase calibration are performed at an auxiliary reference plane ($P_{aux}$) after its own 1-port SOL coaxial calibration:

\begin{equation*}
\begin{pmatrix} a_{aux} \\  b_{aux} \end{pmatrix}=K_{aux}\begin{bmatrix} 1 & \beta_{aux} \\  \gamma_{aux} &  \delta_{aux} \end{bmatrix}.\begin{pmatrix} r_1 \\  r_2  \end{pmatrix}
\label{eq:cal_port_aux}
\end{equation*}

\begin{center}
\includegraphics[width=0.7\linewidth]{CALIBRATION.pdf}
\end{center}

\textbf{$\Rightarrow$ Power} calibration at $P_{aux}$ reference plane requires the connection of a power sensor. According to the measured value, in $dBm$, we can calculate $|K_{aux}|$ such as:
\begin{equation*}
|K_{aux}|=\left|{\frac{10^{(Power-10)/20}}{ r_1 + \beta_{aux} . r_2}}\right|
\label{eq:cal_power}
\end{equation*}

\textbf{$\Rightarrow$ Phase} calibration at $P_{aux}$ is performed by connecting a direct receiver (e.g. $r_3$) at $P_{aux}$:
\begin{equation*}
\arg\{K_{aux}\}=\arg\left\{{\frac{r_3}{ r_1 + \beta_{aux} . r_2}}\right\}
\label{eq:cal_phase}
\end{equation*}

\textbf{$\Rightarrow$ Reciprocity} transfers the absolute calibration from $P_{aux}$ to ports 1 and 2 ($P1$ and $P2$):
\begin{equation*}
K=\pm\sqrt{1/Det\{[M]\}}
\label{eq:reciprocity_1}
\end{equation*}
with
\begin{equation*}
M=\begin{bmatrix} 1 & \beta_1  \\  \gamma_1 &  \delta_1 \end{bmatrix}. {\left [ K_{aux}.\begin{bmatrix} 1 & \beta_{aux}  \\  \gamma_{aux} &  \delta_{aux}  \end{bmatrix} \right]}^{-1}
\label{eq:reciprocity_2}
\end{equation*}
}

%----------------------------------------------------------------------------------------
%   OTHER INSTRUMENTATION
%----------------------------------------------------------------------------------------
\headerbox{Time-domain instrumentation for non-linear devices}{name=instruments,span=2,column=1,row=1, below=introduction}{ % To reduce this block to 1 column width, remove 'span=2'

\begin{center}
\resizebox{0.9\textwidth}{!}{\begin{minipage}{\textwidth}
\begin{tabular}{l l l l}
\toprule
\textbf{Name} & \textbf{Manufacturer} & \textbf{Receivers} & \textbf{Availability}\\
\midrule
MTA (requires two synchronized) & HP & Sampler & Discontinued \\
LSNA & Agilent & Sampler & Discontinued \\
PNA-X + Nonlinear option & Agilent & Mixer & \$\$ \\
ZVA + Nonlinear option & Rohde and Schwarz & Mixer &  \$\$ \\
SWAP X-402 & VTD & Sampler & Discontinued \\
\bottomrule
\end{tabular}
\end{minipage}}
\end{center}
}

%----------------------------------------------------------------------------------------
%   MIXER vs. SAMPLERS
%----------------------------------------------------------------------------------------
\begin{center}
\end{center}
}

%----------------------------------------------------------------------------------------
%   MEASUREMENT SETUP
%----------------------------------------------------------------------------------------
The setup includes \textbf{two LSNAs simultaneously}. One is dedicated to RF (sampler based downconversion), the other one samples directly the LF stimulus. The purpose is to investigate \textbf{low-frequencies $S_{22}$} of the DUT under RF large signal conditions.
\begin{center}
\includegraphics[width=\linewidth]{BENCH.pdf}
\small \textit{Low-frequency measurement of drain supply envelope-bandwidth impedance for supply-modulated PAs}
\end{center}
}

%----------------------------------------------------------------------------------------
%   CONCLUSION
%----------------------------------------------------------------------------------------
This new project will enable a new RF measurement capability by enabling an instrument that currently does not exist on the market. Some additional benefits include:
\vspace{-0.2cm}
\begin{itemize}
\item frequency range extension of NI RF instrument products currently available;
\vspace{-0.2cm}
\item sampler architecture offers a unique multi-scale time analysis possibility (e.g. signal and carrier domains);
\vspace{-0.2cm}
\item can be implemented with various ADCs and downconverters (e.g. THAs);
\vspace{-0.2cm}
\item 100\% LabVIEW environment;
\vspace{-0.2cm}
\item goal is to offer open-source LabVIEW software for user measurement flexibility.
\end{itemize}
}

%----------------------------------------------------------------------------------------
%   REFERENCES
%----------------------------------------------------------------------------------------

%\smaller % Reduce the font size in this block
%\renewcommand{\section}[2]{\vskip 0.05em} % Get rid of the default "References" section title
%\nocite{*} % Insert publications even if they are not cited in the poster

%\bibliographystyle{unsrt}
%\bibliographystyle{IEEEtran}
%\bibliography{biblio} % Use biblio.bib as the bibliography file
%}

%----------------------------------------------------------------------------------------
%   ACKNOWLEDGEMENTS
%----------------------------------------------------------------------------------------

\smaller
This work is funded by National Instruments (Dr. Truchard) through a charitable donation. We would like to acknowledge DARPA (Dr. Greene) and ONR (Dr. Maki) for funding the initial part of this work under grant N00014-11-1-0931. \hfill \tiny \textit{Poster downloaded from} \textbf{www.microwave.fr}
}

\end{poster}

\end{document}

• Welcome to TEX.SE! Could you please add your Minimal Working Example, which illustrates what you have tried to do? – bmv Jan 26 '18 at 14:50

You can renew the \baposter@box@drawbackground@plain macro that fills the boxes to include the fill opacity key:

\makeatletter
\renewcommand{\baposter@box@drawbackground@plain}[2]{\tikzset{box colors/.style={fill=#1,fill opacity=0.2}} \fill[box colors] \baposterBoxGetShape;}
\makeatother


The complete MWE:

\documentclass[a0paper,portrait]{baposter}

\usepackage[font=small,labelfont=bf]{caption} % Required for specifying captions to tables and figures
\usepackage{booktabs} % Horizontal rules in tables
\usepackage{relsize} % Used for making text smaller in some places

\usepackage{amsmath,amsfonts,amssymb,amsthm} % Math packages
\usepackage{eqparbox}

\usepackage{textcomp}

\graphicspath{{figures/}} % Directory in which figures are stored

\definecolor{bordercol}{RGB}{40,40,40} % Border color of content boxes
\definecolor{headercol1}{RGB}{186,215,230} % Background color for the header in the content boxes (left side)
\definecolor{headercol2}{RGB}{120,120,120} % Background color for the header in the content boxes (right side)
\definecolor{headerfontcol}{RGB}{0,0,0} % Text color for the header text in the content boxes
\definecolor{boxcolor}{RGB}{210,235,250} % Background color for the content in the content boxes

\makeatletter
\renewcommand{\baposter@box@drawbackground@plain}[2]{\tikzset{box colors/.style={fill=#1,fill opacity=0.2}} \fill[box colors] \baposterBoxGetShape;}
\makeatother

\begin{document}

\background{ % Set the background to an image (background.pdf)
\begin{tikzpicture}[remember picture,overlay]
\draw (current page.north west)+(-2em,2em) node[anchor=north west]
{\includegraphics[height=1.1\textheight]{background}};
\end{tikzpicture}
}

\begin{poster}{
grid=false,
borderColor=bordercol, % Border color of content boxes
boxColorOne=boxcolor, % Background color for the content in the content boxes
headerfont=\Large\sf\bf, % Font modifiers for the text in the content box headers
textborder=rectangle,
background=user,
headerborder=open, % Change to closed for a line under the content box headers
}
{\includegraphics[scale=0.3]{example-image-a}}
%
%----------------------------------------------------------------------------------------
%   TITLE AND AUTHOR NAME
%----------------------------------------------------------------------------------------
%
{ \bf  \huge {Large Signal Network Analyzer} \\  \Large \it An affordable PXI-based microwave non-linear characterization platform} % Poster title
{\vspace{0.3em} \smaller Tibault Reveyrand$^1$, Scott Schafer$^1$, John Boudreaux$^1$, Takao Inoue$^2$, Zoya Popovi\'c$^1$   \\  % Author names

\smaller $^1$\it {University of Colorado at Boulder} \\ $^2$\it{National Instruments} } % Author email addresses
{\includegraphics[scale=0.45]{example-image-a}} % University/lab logo

%----------------------------------------------------------------------------------------
%   INTRODUCTION
%----------------------------------------------------------------------------------------
\begin{itemize}
\item The goal of this research is to integrate microwave-frequency Large Signal Network Analysis capabilities with commercially available National Instruments' PXI modular instrumentation and LabVIEW environment.
\vspace{-0.2cm}
\item The Microwave Research Group at the University of Colorado has decades of experience in UHF through millimeter-wave transmitters, including recent X-band (10-GHz) MMIC implementations in GaN. Our aim is to extend the frequency range and capabilities of available commercial instrumentation provided by NI.
\vspace{-0.2cm}
\item The proposed instrumentation development will enable new types of measurements such as those required for harmonically-terminated PAs, various transmitter architectures (Doherty, outphasing and supply modulated PAs), as well as microwave transistor rectifiers.  The time-domain characterization is expected to provide dramatic improvement in RF circuit design capabilities.
\end{itemize}
}

%----------------------------------------------------------------------------------------
%   CALIBRATION
%----------------------------------------------------------------------------------------
LSNA calibration algorithm consists of \textbf{3 steps} at each RF frequency: % \cite{verspecht2005large}
\begin{enumerate}
\item A relative VNA calibration creates an error-term matrix related to ports 1 and 2:
\begin{equation*}
\begin{pmatrix} a_ 1 \\  b_1 \\  a_2 \\ b_2 \end{pmatrix}=K\begin{bmatrix} 1 & \beta_1  & 0 & 0\\  \gamma_1 &  \delta_1  & 0 & 0 \\ 0 & 0 & \alpha_2 & \beta_2 \\ 0 & 0 &  \gamma_2 &  \delta_2 \end{bmatrix}.\begin{pmatrix} r_ 1 \\  r_2 \\  r_3 \\ r_4 \end{pmatrix}
\label{eq:cal_2_ports}
\end{equation*}

\item The power calibration gives $|K|$
\item The phase calibration yields $\arg\{K\}$
\end{enumerate}

Power and phase calibration are performed at an auxiliary reference plane ($P_{aux}$) after its own 1-port SOL coaxial calibration:

\begin{equation*}
\begin{pmatrix} a_{aux} \\  b_{aux} \end{pmatrix}=K_{aux}\begin{bmatrix} 1 & \beta_{aux} \\  \gamma_{aux} &  \delta_{aux} \end{bmatrix}.\begin{pmatrix} r_1 \\  r_2  \end{pmatrix}
\label{eq:cal_port_aux}
\end{equation*}

\begin{center}
\includegraphics[width=0.7\linewidth]{example-image-a}
\end{center}

\textbf{$\Rightarrow$ Power} calibration at $P_{aux}$ reference plane requires the connection of a power sensor. According to the measured value, in $dBm$, we can calculate $|K_{aux}|$ such as:
\begin{equation*}
|K_{aux}|=\left|{\frac{10^{(Power-10)/20}}{ r_1 + \beta_{aux} . r_2}}\right|
\label{eq:cal_power}
\end{equation*}

\textbf{$\Rightarrow$ Phase} calibration at $P_{aux}$ is performed by connecting a direct receiver (e.g. $r_3$) at $P_{aux}$:
\begin{equation*}
\arg\{K_{aux}\}=\arg\left\{{\frac{r_3}{ r_1 + \beta_{aux} . r_2}}\right\}
\label{eq:cal_phase}
\end{equation*}

\textbf{$\Rightarrow$ Reciprocity} transfers the absolute calibration from $P_{aux}$ to ports 1 and 2 ($P1$ and $P2$):
\begin{equation*}
K=\pm\sqrt{1/Det\{[M]\}}
\label{eq:reciprocity_1}
\end{equation*}
with
\begin{equation*}
M=\begin{bmatrix} 1 & \beta_1  \\  \gamma_1 &  \delta_1 \end{bmatrix}. {\left [ K_{aux}.\begin{bmatrix} 1 & \beta_{aux}  \\  \gamma_{aux} &  \delta_{aux}  \end{bmatrix} \right]}^{-1}
\label{eq:reciprocity_2}
\end{equation*}
}

%----------------------------------------------------------------------------------------
%   OTHER INSTRUMENTATION
%----------------------------------------------------------------------------------------
\headerbox{Time-domain instrumentation for non-linear devices}{name=instruments,span=2,column=1,row=1, below=introduction}{ % To reduce this block to 1 column width, remove 'span=2'

\begin{center}
\resizebox{0.9\textwidth}{!}{\begin{minipage}{\textwidth}
\begin{tabular}{l l l l}
\toprule
\textbf{Name} & \textbf{Manufacturer} & \textbf{Receivers} & \textbf{Availability}\\
\midrule
MTA (requires two synchronized) & HP & Sampler & Discontinued \\
LSNA & Agilent & Sampler & Discontinued \\
PNA-X + Nonlinear option & Agilent & Mixer & \$\$ \\
ZVA + Nonlinear option & Rohde and Schwarz & Mixer &  \$\$ \\
SWAP X-402 & VTD & Sampler & Discontinued \\
\bottomrule
\end{tabular}
\end{minipage}}
\end{center}
}

%----------------------------------------------------------------------------------------
%   MIXER vs. SAMPLERS
%----------------------------------------------------------------------------------------
\begin{center}
\includegraphics[width=1\linewidth]{example-image-a}
\end{center}
}

%----------------------------------------------------------------------------------------
%   MEASUREMENT SETUP
%----------------------------------------------------------------------------------------
The setup includes \textbf{two LSNAs simultaneously}. One is dedicated to RF (sampler based downconversion), the other one samples directly the LF stimulus. The purpose is to investigate \textbf{low-frequencies $S_{22}$} of the DUT under RF large signal conditions.
\begin{center}
%\includegraphics[width=\linewidth]{BENCH.pdf}
\small \textit{Low-frequency measurement of drain supply envelope-bandwidth impedance for supply-modulated PAs}
\end{center}
}

%----------------------------------------------------------------------------------------
%   CONCLUSION
%----------------------------------------------------------------------------------------
This new project will enable a new RF measurement capability by enabling an instrument that currently does not exist on the market. Some additional benefits include:
\vspace{-0.2cm}
\begin{itemize}
\item frequency range extension of NI RF instrument products currently available;
\vspace{-0.2cm}
\item sampler architecture offers a unique multi-scale time analysis possibility (e.g. signal and carrier domains);
\vspace{-0.2cm}
\item can be implemented with various ADCs and downconverters (e.g. THAs);
\vspace{-0.2cm}
\item 100\% LabVIEW environment;
\vspace{-0.2cm}
\item goal is to offer open-source LabVIEW software for user measurement flexibility.
\end{itemize}
}

%----------------------------------------------------------------------------------------
%   REFERENCES
%----------------------------------------------------------------------------------------

%\smaller % Reduce the font size in this block
%\renewcommand{\section}[2]{\vskip 0.05em} % Get rid of the default "References" section title
%\nocite{*} % Insert publications even if they are not cited in the poster

%\bibliographystyle{unsrt}
%\bibliographystyle{IEEEtran}
%\bibliography{biblio} % Use biblio.bib as the bibliography file
%}

%----------------------------------------------------------------------------------------
%   ACKNOWLEDGEMENTS
%----------------------------------------------------------------------------------------

\smaller
This work is funded by National Instruments (Dr. Truchard) through a charitable donation. We would like to acknowledge DARPA (Dr. Greene) and ONR (Dr. Maki) for funding the initial part of this work under grant N00014-11-1-0931. \hfill \tiny \textit{Poster downloaded from} \textbf{www.microwave.fr}
}

\end{poster}

\end{document}


You can use \pgfsetfillopacity{0.6} to make the boxes semi-transparent.

\documentclass[a0paper,portrait]{baposter}

\usepackage{lipsum}
\definecolor{boxcolor}{RGB}{210,235,250}

\begin{document}

\background{ % Set the background to an image (background.pdf)
\begin{tikzpicture}[remember picture,overlay]
\draw (current page.north west)+(-2em,2em) node[anchor=north west]
{\includegraphics[height=1.1\textheight]{example-grid-100x100bp}};
\end{tikzpicture}
}

\begin{poster}{
boxColorOne=boxcolor,
textborder=rectangle,
background=user,
}
{}
{}
{}
{}
\pgfsetfillopacity{0.6}