How to make custom attributes translatable

Sorry I didn’t react to this sooner, but you found the basic method of doing it.
Although the names change for the attribute fields depending on the count, so in this particulate case I’d use the language tags …

Hm, I’m not sure if I understand what you’re trying to say …
What do you mean with “so in this particular case I’d use the language tags”?
What are the language tags? – “[:en]English[:de]Deutsch[:]” ??

The qtranslate documentations explains several ways to “designate a field as multilinugal”
Definition in the Json file and special reserved “classes” seem to be the most common/easiest way. From what I’ve seen multilingual field content will only be shown in different languages if a field has been declared as a multilingual field.

Are you saying that this is not necessary?
If so, what do I need to do to be able to enter multilingual content in attributes – without adding new ID’s and specifying them in the Json file.

Sorry, but this is the first time I work with qtranslate-x.
Cheers,
Bernd