Wiktionary
dyed in the wool
(context idiomatic English) (alternative spelling of dyed-in-the-wool English) (Set in one's ways, steadfast.) v
(en-pastdye in the wool)
Usage examples of "dyed in the wool".
Despite his protests that he was a monk dyed in the wool of his monastery, Padraig, too, came in for the same treatment.
She'd always thought Dennis was a stolid sort, a dyed in the wool rationalist.