Why are some PDFs refused by the Lulu printer?
There are quick and easy answers and there are many additional unknowns. The first is that PDFs created using Ghostscripts 7.04 and 7.05 are rejected because these versions are likely to produce incompatible PDFs. In addition, Lulu staff have pointed at font embedding as an issue and have strongly recommended embedding all fonts and avoiding subset embedding. In particular, the Lulu system will reject PDFs that are created using fonts that are not embedded. Interestingly, Adobe’s Acrobat Distiller is the “gold standard” for PDF creationware and Lulu’s staff regularly suggest that making PDFs with Distiller is the best way to make a printable PDF. This is curious since Distiller insists on subsetting embedded True Type fonts. Obviously there is something contradictory about the current Lulu recommendations. What is clear is that most problems come from books submitted as multiple PDFs that also have fonts which are subset embedded. Adobe Acrobat and perhaps some other applications have
