Foil stamping is available on Hardcover Linen with Dust Jacket products only. The foil stamp is placed on the spine of your book and cannot exceed 42 characters. Lulu’s foil stamping supports the following characters:Roman characters sets (A-Z, 0-9);',./!`^&*()~+:?"ˇ˘°´¨¯-ÀÁÃĀÄĂĆČÇĎÈÉËĒĔĚĞÌÍĨÏĪĬĽĹÑŃŇÒÓÕÖŌŎŔŘŚŠŤÙÚŨŪÜŬÝŸŹŽUnsupported Characters:Lower case characters_ (underscore)Punctuation marks or accents used as decorative elements in lieu of a titleNon-Roman character sets (Cyrillic, Arabic, Hebrew, Farsi, Chinese, Japanese, Thai, etc.)The JSON for the foil spine text will look like the example below (with your own text in the bolded areas):"line_items": [ { "external_id": "item-reference-1", "printable_normalization": { "cover": {}, "interior": {}, "pod_package_id": "0600X0900BWSTDPB060UW444MXX", "foil_stamp_author_text": "foil book", "foil_stamp_title_text": "item-reference-1" }, "quantity": 30, "title": "My Book" } ]