var doc = new PdfDocument();
doc.Info.Title = "Multi-Page Document";
doc.Language = "en-US";
doc.DisplayDocTitle = true;
var root = doc.EnableTaggedPdf();

// Create a reusable header (Form XObject)
var header = doc.CreateFormXObject(612, 30);
header.DrawLine(72, 0, 540, 0, new PdfDrawOptions {
    StrokeColor = new PdfColor(0.7, 0.7, 0.7)
});
header.AddText("Multi-Page Document — ObviousPDF",
    72, 8, new PdfTextOptions {
        Font = StandardFont.HelveticaOblique,
        FontSize = 8,
        Color = new PdfColor(0.5, 0.5, 0.5)
    });

// Generate pages
string[] chapters = { "Introduction", "Core Concepts", "Conclusion" };
for (int i = 0; i < chapters.Length; i++)
{
    var page = doc.AddPage();

    // Reusable header as artifact
    page.BeginArtifact(PdfArtifactType.Pagination);
    page.AddFormXObject(header, 0, 762);
    page.EndArtifact();

    // Tagged chapter heading
    var sect = root.AddChild(StructureType.Sect);
    var h1 = sect.AddChild(StructureType.H1);
    page.AddTaggedText(h1,
        $"Chapter {i + 1}: {chapters[i]}",
        72, 720, new PdfTextOptions {
            Font = StandardFont.HelveticaBold,
            FontSize = 20
        });

    // Page number artifact
    page.AddArtifactText(
        $"Page {i + 1} of {chapters.Length}",
        270, 30, PdfArtifactType.Pagination);
}

doc.Save("multi_page.pdf");