LibreOffice 24.8 Help
Select a line drawing object in a document.
Choose Format - Line and click the Line Styles tab.
Specify the line options that you want.
To specify the length of the line as a percentage of the line thickness, select Fit to line thickness.
Click Add.
Enter a name for the line style and click OK.
To save the line style in a custom line style list, click the Save Line Styles icon.
Click Close to close the dialogue.