The best formats for scanning and storing large format documents are PDF (Portable Document Format) and TIFF (Tagged Image File Format). Both formats offer excellent image quality, searchable metadata, and high compatibility.
Choosing between these two options depends largely on your requirements, such as the intended use of the scanned document, image quality, file size, and whether the document contains only text, images, or a combination of both. Read more about the differences between PDF and TIFF files.