I inserted text into a PDF document with Preview in a custom font I had installed on my Mac. When I transferred it to my iPad and opened it with Notability, to my horror all the text had been removed. When I opened it in PDF Expert, it was there but the font had reverted to Helvetica. Naturally this isn't something I want, as I expect the recipient to see exactly what I'm seeing in a PDF file.
I presume this happened because Preview wasn't embedding the font into the PDF (although strangely the file size became significantly larger, suggesting that it had). What am I doing wrong, and what's the correct way to embed a font that you use in a PDF file?