SnapToGrid

public bool SnapToGrid { get; set; }

Document doc = new Document();
DocumentBuilder builder = new DocumentBuilder(doc);

// Enable pitching, and then use it to set the number of lines per page in this section.
// A large enough font size will push some lines down onto the next page to avoid overlapping characters.
builder.PageSetup.LayoutMode = SectionLayoutMode.LineGrid;
builder.PageSetup.LinesPerPage = 15;

builder.ParagraphFormat.SnapToGrid = true;

for (int i = 0; i < 30; i++)
    builder.Write("Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. ");

doc.Save(ArtifactsDir + "PageSetup.LinesPerPage.docx");