Embedding Type 1C fonts using LuaLaTeX

Question

As pointed out in the answer to PDF file size with LuaLaTeX vs XeLaTeX, the difference between using Type 1 and Type 1C fonts in two documents made a big difference in file size.

File size is important in the PDF files I'm working with. So my question is can you force LuaLaTeX to embed a Type 1C font instead of Type 1? This is something XeLaTeX can do (and in the case of the question cited above, did automatically).

The font I'm working with is Gill Sans MT (I believe it comes with Adobe CS). While I'm not opposed to changing fonts, I'd still like to know how LuaLaTeX decides how to embed fonts and how it can be changed.

Answer 1

I do not know how to make lualatex output Type 1C fonts. However, you may be able to use ps2pdf to convert a PDF containing Type 1 fonts to another PDF containing Type1C fonts. You should carefully choose parameters to ps2pdf. For example:

newell:~/latex/help $ du -h plain.pdf
60K plain.pdf
newell:~/latex/help $ pdffonts plain.pdf 
name                                 type              emb sub uni object ID
------------------------------------ ----------------- --- --- --- ---------
BZAAVM+NimbusSanL-Bold               Type 1            yes yes no      17  0
YCENSD+LMMathItalic12-Regular        Type 1            yes yes no      18  0
KDKAQG+CMSS12                        Type 1            yes yes no      19  0
IDSSCN+NimbusSanL-Regu               Type 1            yes yes no      20  0
ZIJBJP+NimbusSanL-ReguItal           Type 1            yes yes no      21  0
SEAJVD+NimbusSanL-BoldItal           Type 1            yes yes no      22  0
SQTJQN+LMMathSymbols10-Regular       Type 1            yes yes no      23  0
newell:~/latex/help $ ps2pdf -dPDFSETTINGS=/prepress -dAutoRotatePages=/None -dEmbedAllFonts=true -dMaxSubsetPct=100 -dSubsetFonts=true -dAutoFilterColorImages=false -dAutoFilterGrayImages=false -dDownsampleColorImages=false -dDownsampleGrayImages=false -dDownsampleMonoImages=false plain.pdf new.pdf
newell:~/latex/help $ du -h new.pdf
36K new.pdf
newell:~/latex/help $ pdffonts new.pdf 
name                                 type              emb sub uni object ID
------------------------------------ ----------------- --- --- --- ---------
OJEPRS+NimbusSanL-BoldItal           Type 1C           yes yes no      23  0
OJIXHX+LMMathSymbols10-Regular       Type 1C           yes yes no      25  0
CYORGJ+NimbusSanL-Bold               Type 1C           yes yes no      13  0
MZVUTG+LMMathItalic12-Regular        Type 1C           yes yes yes     15  0
PWIYDZ+CMSS12                        Type 1C           yes yes no      17  0
QBTHSF+NimbusSanL-Regu               Type 1C           yes yes no      19  0
XMYGAL+NimbusSanL-ReguItal           Type 1C           yes yes no      21  0

Answer 2

Luatex never writes Type1C fonts. You will get smaller pdfs if you use OpenType/TrueType fonts instead of Type1 (luatex writes CIDType0 fonts for those) but otherwise pstopdf is the alternative. Unless someone supplies a patch, this situation is unlikely to change.

Answer 3

If you are not forced to use LuaLaTeX for some reason, why don't you use pdfLaTeX and shrink the PDF afterwards by using the formidable python programm pdfsizeopt.py? See here: How to create small PDF files for the Internet?