- Increase sans font weight from regular to medium.

- Fix multiparagraph boxout formatting.
- Add NumberWord command and option for part titles.

packages/Titles.sty

@@ -3,10 +3,42 @@
 	Title formatting definitions.
 }
 
+\NewExpandableDocumentCommand{\NumberWord}{O{lowercase} m}{
+	\use:c {text_#1:n} {
+		\int_case:nn {#2} {
+			{0} {zero}
+			{1} {one}
+			{2} {two}
+			{3} {three}
+			{4} {four}
+			{5} {five}
+			{6} {six}
+			{7} {seven}
+			{8} {eight}
+			{9} {nine}
+			{10} {ten}
+			{11} {eleven}
+			{12} {twelve}
+			{13} {thirteen}
+			{14} {fourteen}
+			{15} {fifteen}
+			{16} {sixteen}
+			{17} {seventeen}
+			{18} {eighteen}
+			{19} {nineteen}
+		}
+	}
+}
+
+
 \bool_if:NF \g_roman_bool {
 	\renewcommand{\thepart}{\arabic{part}}
 }
 
+\bool_if:NT \g_number_word_bool {
+	\renewcommand{\thepart}{\NumberWord[titlecase_all]{\value{part}}}
+}
+
 \titleformat{\part}[display]{
 	\normalfont\sbfamily\huge
 }{