The PaperSize Class .. autoclass:: pypdf.PaperSize :members: :undoc-members: :show-inheritance: Add blank page with PaperSize from pypdf import PaperSize, PdfReader, PdfWriter pdf_reader = PdfReader("sample.pdf") pdf_writer = PdfWriter() pdf_writer.append_pages_from_reader(pdf_reader) pdf_writer.add_blank_page(PaperSize.A8.width, PaperSize.A8.height) with open("output.pdf", "wb") as output_stream: pdf_writer.write(output_stream) Insert blank page with PaperSize from pypdf import PaperSize, PdfReader, PdfWriter pdf_reader = PdfReader("sample.pdf") pdf_writer = PdfWriter() pdf_writer.append_pages_from_reader(pdf_reader) pdf_writer.insert_blank_page(PaperSize.A8.width, PaperSize.A8.height, 1) with open("output.pdf", "wb") as output_stream: pdf_writer.write(output_stream)