What is a word or term with an opposite or complementary meaning to "flaky person"? [closed]

One good candidate would be "reliable", but I am looking for a word with more direct connotations to social behavior like flaky has.


I offer solid as a complementary word to flaky, in a similar register.
Lexico has:

solid
ADJECTIVE

4 Dependable; reliable.
The real man was solid, dependable, loyal, uncomplaining, quick to act and slow to forgive.