diff --git a/.github/workflows/latex-pdf.yml b/.github/workflows/latex-pdf.yml
index c42dca9..6e29c00 100644
--- a/.github/workflows/latex-pdf.yml
+++ b/.github/workflows/latex-pdf.yml
@@ -13,6 +13,7 @@ jobs:
               uses: xu-cheng/latex-action@v2
               with:
                   root_file: main.tex
+                  latexmk_shell_escape: true
 
             - name: Upload Artifact
               uses: actions/upload-artifact@v2
diff --git a/.github/workflows/publish-latest.yml b/.github/workflows/publish-latest.yml
index a65abc3..a5f5d6d 100644
--- a/.github/workflows/publish-latest.yml
+++ b/.github/workflows/publish-latest.yml
@@ -19,6 +19,7 @@ jobs:
         with:
           working_directory: 'taoe3'
           root_file: 'main.tex'
+          latexmk_shell_escape: true
 
       - name: Checkout gh_pages branch
         uses: actions/checkout@v2
diff --git a/.gitignore b/.gitignore
index 9b1324c..c38f068 100644
--- a/.gitignore
+++ b/.gitignore
@@ -38,3 +38,7 @@
 # latexrun
 latex.out/
 
+## Tikz externalize files
+*.makefile
+*.figlist
+*.auxlock
diff --git a/main.pdf b/main.pdf
index ae9d5a7..01cd1fb 100644
Binary files a/main.pdf and b/main.pdf differ
diff --git a/taoesolutions.sty b/taoesolutions.sty
index 8dfb01f..a81b8aa 100644
--- a/taoesolutions.sty
+++ b/taoesolutions.sty
@@ -2,6 +2,7 @@
 
 \usepackage{circuitikz}
 \usepackage{pgfplots}
+\usepackage{environ}
 \usepackage{amsmath}
 \usepackage{cancel}
 \usepackage{enumitem}
@@ -13,6 +14,10 @@
 ]{geometry}
 \usepackage[toc]{multitoc}
 
+\usetikzlibrary{external}
+\tikzexternalize[prefix=tikz-cache/]
+% \tikzexternalize[prefix=tikz-cache/, mode=list and make]
+
 % Remove the "Chapter" label on each chapter
 \usepackage{titlesec}
 \titleformat{\chapter}[display]
@@ -43,39 +48,63 @@
 \newcommand{\ave}{\ensuremath{\text{ave}}} % average
 \newcommand{\eq}{\ensuremath{\text{eq}}} % equivalent 
 
-\newenvironment{circuit}[2]% param1=label, param2=caption
-    {
-        \begin{figure}[H]
+\NewEnviron{circuit}[2]{%
+    \begin{figure}[H]
         \caption{#2}
         \label{#1}
-        
-        \begin{center} 
-        % \centering
-        \begin{circuitikz}[american]\draw
-    }
-    {
+        \begin{center}
+        \begin{tikzpicture}[american]\draw
+            \BODY
         ;
-        \end{circuitikz}
+        \end{tikzpicture}
         \end{center}
-        \end{figure}
-    }
+        \end{figure}}
+
+% \newenvironment{circuit}[2]% param1=label, param2=caption
+%     {
+%         \begin{figure}[H]
+%         \caption{#2}
+%         \label{#1}
+        
+%         \begin{center} 
+%         % \centering
+%         \begin{tikzpicture}[american]\draw
+%     }
+%     {
+%         ;
+%         \end{tikzpicture}
+%         \end{center}
+%         \end{figure}
+%     }
 
-\newenvironment{plot}[2]% param1=label, param2=caption
-    {
-        \begin{figure}[H]
+\NewEnviron{plot}[2]{%
+    \begin{figure}[H]
         \caption{#2}
         \label{#1}
-        
-        \begin{center} 
-        % \centering
+        \begin{center}
         \begin{tikzpicture}[scale=0.8, samples=200]\draw
-    }
-    {
+            \BODY
         ;
         \end{tikzpicture}
         \end{center}
-        \end{figure}
-    }
+        \end{figure}}
+
+% \newenvironment{plot}[2]% param1=label, param2=caption
+%     {
+%         \begin{figure}[H]
+%         \caption{#2}
+%         \label{#1}
+        
+%         \begin{center} 
+%         % \centering
+%         \begin{tikzpicture}[scale=0.8, samples=200]\draw
+%     }
+%     {
+%         ;
+%         \end{tikzpicture}
+%         \end{center}
+%         \end{figure}
+%     }
 % Set first level of list to (a) format
 \setlist[enumerate,1]{label=(\alph*)}
 
diff --git a/tikz-cache/.gitignore b/tikz-cache/.gitignore
new file mode 100644
index 0000000..7d06c29
--- /dev/null
+++ b/tikz-cache/.gitignore
@@ -0,0 +1,6 @@
+# This tikz-cache folder is here to cache the tikz images.
+# It is needed by the \tikzpackage{external} library.
+# This folder is not automatically generated, so it's tracked in version control
+# to prevent new users from seeing cryptic compile errors.
+*
+!.gitignore