What are things to avoid in making PDFs for Lulus printer?
If at all possible try to make your book with a single application and produce a single PDF from that application. Do not edit your PDF in Acrobat to fix minor mistakes because that editing process is unlikely to properly embed the fonts used in the editing. Make your PDF with all fonts embedded and with subsetting not selected. If you make your PDF with Acrobat Distiller and you use True Type fonts (nearly all fonts on typical Windows systems) then some fonts will invariably be subsetted. PDFWriter, another Acrobat application for creating a PDF through a virtual printer may embed more completely than Distiller. (However, it is not yet clear PDFWriter makes PDFs that are any more compliant with Lulu’s printer.) Subsetted embedding by Distiller may not be a problem for submitting a single PDF. It may be an issue if you submit multiple PDFs that Lulu must combine into one.