We use Arbortext 7.0 authoring tool and APE to export to PDF. Our stylesheet is using Arial Unicode.
Upon initial review of our PDF the Operations Manual appears okay at 100% view.
But upon closer inspection, the PDF is duplicating the letters in our titles.
This happens, we thought, when it was just our headers that were bolded.
But upon further investigation, it appears that anything we bold has double letters.
Is it because of the font? In Arbortext 6 we used Helen Pro, a font we purchased without issue, except we had to have different fonts for Asian languages.
You have hit the nail on the head, when the APP typesetting engine cannot find a bold version of a font it will double up the letters to give the appearance of bold type. Arial Unicode MS does not have a bold version so that would explain the behaviour.
The solution is to set your font to Arial but allow Arial Unicode MS to be used as a fallback font. In the case where you are printing some characters that are not available in regular Arial it will fallback to the Unicode font that has a more complete set of glyphs available.
Also, you will find a similar problem with italics. If you don't have an italic font available it will slant the text by applying a skew transformation to the characters. This looks OK most of the time but does not give a true italics typeface as intended by the font designer.
You can select the main style font according to language, but have a "cover-all" fallback font such as Arial Unicode MS for those symbols that are not covered by the current style language. e.g. you could have a Sanskrit font active for documents using that language but still have Arial Unicode MS as a fallback to display scientific symbols that are not covered by Sanskrit.