# tcolorbox: Breakable option not working

I am currently trying to write a roadmap for my master thesis, with a nice design. I want to use multiple tcolorbox boxes for each chapter and stack them. The boxes should break at the end of each page, otherwise the pages get empty pretty fast. I added the option breakable but nothing happens. Enforce breakable does not seem to work as well. Any ideas? Am I doing something wrong?

Here is the code for one box:

\begin{tcolorbox}[before skip=\baselineskip,breakable,enhanced,sharpish corners, colframe=black!6!white, colback =black!6!white, sidebyside, lefthand width = 0cm,drop lifted shadow]
\tcblower
\textbf{Concepts draft:}
This chapter describles the initial development of the concepts and the solution considered in the early phases of the project.
\begin{enumerate}
\item Description of the different process steps and possible combinations.
\item Listing of the retained concepts to focus on during the project.
\end{enumerate}
\end{tcolorbox}


PS: The flaticonbox command is a personal one, which basically ads a pdf image in the left column, with a defined size.

Here is the final result, which goes on like this for 4 pages. As you can see, I have a lot of free space a the end of the pages:

EDIT: This is a compilable code for testing

\documentclass{article}
\usepackage[demo]{graphicx}
\usepackage[T1]{fontenc}
\usepackage[bitstream-charter]{mathdesign}
\usepackage[skins,xparse,breakable]{tcolorbox}
\usepackage{setspace}
\onehalfspacing
\setlength{\parindent}{0pt}
\setlength{\parskip}{2.0ex plus0.5ex minus0.2ex}

\begin{document}
\begin{tcolorbox}[before skip=\baselineskip,enhanced,breakable,sharpish corners, colframe=black!3!white, colback =black!3!white, sidebyside, lefthand width = 0cm,drop lifted shadow]
Icon
\tcblower
\textbf{State of the art:} Context, technical background and choice of the assessment methods.
\begin{enumerate}
\item Description of the initial context at Volvo construction equipment and description of the chosen sub-assemblies for the Thesis. The mechanical characteristics of the sub-assemblies will also be described, since they are from importance for the project
\item Description of the state of current production. The focus is set on the welding department, and more particularly on the workstations where the sub-assemblies still produced at VCE.
\item Description of the welding technology and welding state of the art. This section also describes the type of welds used along the project, and the different equipment usable to achieve them.
\end{enumerate}
\end{tcolorbox}

\begin{tcolorbox}[before skip=\baselineskip,breakable,enhanced,sharpish corners, colframe=black!6!white, colback =black!6!white, sidebyside, lefthand width = 0cm,drop lifted shadow]
Icon
\tcblower
\textbf{Concepts draft:}
This chapter describles the initial development of the concepts and the solution considered in the early phases of the project.
\begin{enumerate}
\item Description of the different process steps and possible combinations.
\item Listing of the retained concepts to focus on during the project.
\end{enumerate}
\end{tcolorbox}

\begin{tcolorbox}[before skip=\baselineskip,enhanced,sharpish corners, colframe=black!9!white, colback =black!9!white, sidebyside, lefthand width = 0cm,drop lifted shadow,enforce breakable]
Icon
\tcblower
\textbf{Fixture design:}
This chapter is focused on the development of the welding fixture, which represent a major amount of the total thesis work due to it's innovations.
\begin{enumerate}
\item Assessment of the fixture requirements
\item First concept development and assessment: Fixture with standard locators.
\item Second concept: Smart fixture without locators. This concept seemed to be the most suitable for the project application and this chapter focuses grandly on a multitude of analysis to assess the feasability of such a fixture (exact layout for maximum flexibility, security, resistance to a welding environment, gripping force, etc.).
\end{enumerate}
\end{tcolorbox}

\begin{tcolorbox}[before skip=\baselineskip,enhanced,sharpish corners, colframe=black!12!white, colback =black!12!white, sidebyside, lefthand width = 0cm,drop lifted shadow,enforce breakable]
Icon
\tcblower
\textbf{Tack welding assembly design:}
This chapter is focused on the design of the tack welding process for all chosen sub-assemblies and it's characteristics.
\begin{enumerate}
\item Tack welding characteristics: Tack welding Do's and don'ts
\item Definition and assessment method of the tack welds.
\item Distortion compensation: Assessment of the geometry variation and impact on quality because of thermal deformation when tack welding without a dedicated fixture.
\item Original curvature of the plate: Assessment of the geometry variation and impact on quality due to the initial geometry variation of the plate when tack welding without a dedicated fixture.
\end{enumerate}
\end{tcolorbox}

\begin{tcolorbox}[before skip=\baselineskip,enhanced,sharpish corners, colframe=black!15!white, colback =black!15!white, sidebyside, lefthand width = 0cm,drop lifted shadow,enforce breakable]
Icon
\tcblower
\textbf{Design of the production cell:}
This chapter finalizes the development of the concepts and comprehends global assessments.
\begin{enumerate}
\item Cycle time analysis: Assessment of the time needed to tack weld, weld and quality check all sub-assemblies. Definition of the required workforce and equipment to achieve weekly production target, depending on the concept used. Implementation and verification with Siemens Tecnomatix.
\item Definition and assessment of the means of production for each concept, in particular the sensors for the tack welding workcell with HRI.
\item Final concepts description
\end{enumerate}
\end{tcolorbox}

\begin{tcolorbox}[before skip=\baselineskip,enhanced,sharpish corners, colframe=black!18!white, colback =black!18!white, sidebyside, lefthand width = 0cm,drop lifted shadow,enforce breakable]
Icon
\tcblower
\textbf{Final concepts assessment:}
This chapter assesses the concepts that were not eliminated along the project and defines which one ar the most suited.
\begin{enumerate}
\item Assessment criteria and method
\item Final assessment (cost,...)
\item Discussion of the results
\end{enumerate}
\end{tcolorbox}
\end{document}

• Welcome, can you make thecode compilable, so we can reproduce the issue with a real document and test possible solutions? – Johannes_B Jul 14 '16 at 9:21
• See the description of the sidebyside option: "The resulting box is unbreakable". You will have to insert your picture in a different way. – Ulrike Fischer Jul 14 '16 at 9:26
• @Johannes_B: code added. – clemferry Jul 14 '16 at 9:48
• @UlrikeFischer: I tried without images, it does not work as well (see compilable code in EDIT) – clemferry Jul 14 '16 at 9:48
• Remove the sidebyside option. – Ulrike Fischer Jul 14 '16 at 9:50

Yes, sidebyside boxes are unbreakable, but there's no need for using sidebyside boxes to obtain these results. A simple left margin and an overlayed icon can do the work and tcolorboxes will break.

Following code defines mybox with two mandatory and one optional parameters. Mandatory are the percentage of back for background color and the icon figure name. The optional parameter can be used to apply changes to a particular box.

\documentclass{article}
\usepackage[]{graphicx}
\usepackage[T1]{fontenc}
\usepackage[bitstream-charter]{mathdesign}
\usepackage[skins,xparse,breakable]{tcolorbox}
\usepackage{setspace}
\onehalfspacing
\setlength{\parindent}{0pt}
\setlength{\parskip}{2.0ex plus0.5ex minus0.2ex}

\newtcolorbox{mybox}[3][]{
enhanced,
breakable,
notitle,
sharpish corners,
before skip=\baselineskip,
colframe=black!#2!white,
colback=black!#2!white,
leftupper=1.5cm,
overlay={\node[anchor=west] at ([xshift=2mm]frame.west) {\includegraphics[width=1cm]{#3}};},
#1
}

\begin{document}
\begin{mybox}{3}{example-image-A}
\textbf{State of the art:} Context, technical background and choice of the assessment methods.
\begin{enumerate}
\item Description of the initial context at Volvo construction equipment and description of the chosen sub-assemblies for the Thesis. The mechanical characteristics of the sub-assemblies will also be described, since they are from importance for the project
\item Description of the state of current production. The focus is set on the welding department, and more particularly on the workstations where the sub-assemblies still produced at VCE.
\item Description of the welding technology and welding state of the art. This section also describes the type of welds used along the project, and the different equipment usable to achieve them.
\end{enumerate}
\end{mybox}

\begin{mybox}{6}{example-image-B}
\textbf{Concepts draft:}
This chapter describles the initial development of the concepts and the solution considered in the early phases of the project.
\begin{enumerate}
\item Description of the different process steps and possible combinations.
\item Listing of the retained concepts to focus on during the project.
\end{enumerate}
\end{mybox}

\begin{mybox}[colback=red!5,colframe=red!5]{0}{example-image-C}
\textbf{Fixture design:}
This chapter is focused on the development of the welding fixture, which represent a major amount of the total thesis work due to it's innovations.
\begin{enumerate}
\item Assessment of the fixture requirements
\item First concept development and assessment: Fixture with standard locators.
\item Second concept: Smart fixture without locators. This concept seemed to be the most suitable for the project application and this chapter focuses grandly on a multitude of analysis to assess the feasability of such a fixture (exact layout for maximum flexibility, security, resistance to a welding environment, gripping force, etc.).
\end{enumerate}
\end{mybox}

\begin{mybox}{12}{example-image}
\textbf{Tack welding assembly design:}
This chapter is focused on the design of the tack welding process for all chosen sub-assemblies and it's characteristics.
\begin{enumerate}
\item Tack welding characteristics: Tack welding Do's and don'ts
\item Definition and assessment method of the tack welds.
\item Distortion compensation: Assessment of the geometry variation and impact on quality because of thermal deformation when tack welding without a dedicated fixture.
\item Original curvature of the plate: Assessment of the geometry variation and impact on quality due to the initial geometry variation of the plate when tack welding without a dedicated fixture.
\end{enumerate}
\end{mybox}

\begin{mybox}{15}{example-image-A}
\textbf{Design of the production cell:}
This chapter finalizes the development of the concepts and comprehends global assessments.
\begin{enumerate}
\item Cycle time analysis: Assessment of the time needed to tack weld, weld and quality check all sub-assemblies. Definition of the required workforce and equipment to achieve weekly production target, depending on the concept used. Implementation and verification with Siemens Tecnomatix.
\item Definition and assessment of the means of production for each concept, in particular the sensors for the tack welding workcell with HRI.
\item Final concepts description
\end{enumerate}
\end{mybox}

\begin{mybox}{18}{example-image-B}
\textbf{Final concepts assessment:}
This chapter assesses the concepts that were not eliminated along the project and defines which one ar the most suited.
\begin{enumerate}
\item Assessment criteria and method
\item Final assessment (cost,...)
\item Discussion of the results
\end{enumerate}
\end{mybox}
\end{document}