Back in the late 80s/early 90s there was a kind of tie that men would wear with plaid flannel shirts. They were usually drab-colored and had a bumpy knitted texture to it. They didn’t taper off into a V-shape like most ties, but ended with a straight line, like: |_| They seemed less formal than regular ties.
Were these ever given a specific name?
You mean knit ties? http://www.narrowties.com/knit_ties.htm
Yup, those are the ones. Thanks, that was fast.
I refered to them as ugly.
I always heard them referred to as ‘rep’ ties.
That’s odd, because the standard definition of “rep tie” seems to be a woven silk necktie like this one: the sort of thing most people mean when they say “necktie”. “Rep” specifically refers to a weave pattern with longitudinal ribs, which would not apply to a knitted tie.
You are quite correct.
And you are not. 
Seriously, although they were (and still would be) out of place with formal business attire, they went very well with casual plaid shirts, as mentioned in the OP.