The PHP TCPDF library allows you to "not embed" core fonts and CID-0 fonts.
"The fonts that could be not embedded are only the standard core fonts and CID-0 fonts."
I see that they have created their own PHP files with the cmap tables for each font/language. They seem to be based on the ArialUnicodeMS font.
Here is a sample from their korean font (cid0kr.php):
// TCPDF FONT FILE DESCRIPTION
$desc=array('Flags'=>32,'FontBBox'=>'[-1011 -330 2260 1078]','ItalicAngle'=>0,'Ascent'=>1069,'Descent'=>-271,'Leading'=>0,'CapHeight'=>716,'XHeight'=>518,'StemV'=>34,'StemH'=>15,'AvgWidth'=>441,'MaxWidth'=>2259,'MissingWidth'=>1000);
So my question is: Is there a similar facility in PDFClown to be able to specify the characters to be displayed without actually embedding the font?
Thanks for any tips.
I managed to get Chinese, Japanese, and Korean fonts working as CIDType0, non-embedded fonts by subclassing the Font class and creating a parser TCPDF's fonts. It is working well, but I am having difficulty getting the widths of fonts to render correctly. If I use the character widths in the font and use the /W  array, it places too much space between the characters.
If I make it so that the glyphWidths map stores the correct widths, but I store the widths in the /W array (inside the PDF document) scaled down by a factor of 2, it approximately comes out right.
Any idea what would cause this?
I know this doesn't offer much of a clue as to where to start
Got it all sorted out. I was encoding each character with 4 bytes. Should have been using only 2 bytes. I have uploaded the library to GitHub so you can use Chinese, Japanese, and Korean fonts now easily in PDFClown.