To save space, PDF creators often "subset" CID fonts, including only the characters used in that specific document. This can sometimes cause issues when trying to edit the PDF later. Academic and Professional Requirements What are CID or composite fonts?
CID font technology represents a pivotal advancement in digital typography, solving the critical problem of managing large character sets required for global communication. By separating the glyph outlines (CIDFont) from the character encoding (CMap), Adobe created a flexible, scalable system that remains the backbone of high-quality printing and PDF rendering for CJK languages. While end-users today interact mostly with OpenType containers, the underlying logic of CID technology continues to power the display of billions of non-Latin characters worldwide. cid font