I would like to see “mullion” used in cases for windows and doors where “muntin” is overused and used incorrectly. Mullion are the bigger/heavier horizontal or vertical members. Muntins are the wood/aluminum dividers separating panes/ thermal units no-a-days. Look it up! 🙂 Thanks.
Red-Seal carpenter here from Canada–did a bit of glazing as well in my day. Cheers