Mastering in Cubase

I know there are a mountain of books, videos etc.
and yes I am consulting as many as I can

when creating a stereo mix for mastering, what is the best format to export to for mastering?

If it is for cd or universal media player format you ditter and save your mix to 16 bits 44.1.
If it is for archiving or postmastering (if you send it to a mastering company) you bettter render to 24 bit or higher, samplerate same as project audio (no conversion), no exessive limiting or maximizing (yet :laughing: ) if possible.

In general: as long as you don’t compress (mp3) or use DRM (WMA) , most file formats are “sort of equal” as you can always convert. Lossless (Flac) is also fine as you can restore to uncompressed audio at wish.