No disrespect to the OP, memory is a funny thing, I often misremember things myself. But this is my theory.
When I first started playing and heard of flatwounds, I wrongly assumed if roundwounds had a round cross-section then surely flatwounds must have flat sides, like a square or rectangular cross section. I think the OP made this assumption as well, and since the strings were only on the bass for a short time misremembered what they were.
In actuality, it was on deliberately buying what I thought were flat wounds only to get what I will now more precisely describe as nylon-dipped round wounds in tan packaging. That is the ignorance of a noob 19yr old kid. The vague recollection of tan packaging suggests those could have been Rotosounds, Ernie balls, daddarios or even a Markley.
I've more than often described these were physically rectangular. It was later I bought flats thinking that's what it meant because of my experience with actual flatt-ish, physically rectangular 'strings'. That music store was not Daddy's Junky Music over by the highway, it was downtown on Manchester in Manchester, NH. The name of that music store, whether Macnhester is astreet, blvd or avenue, those are fiddly memory bits that get jangled. That there was a music store that I could go on to vaguely describe and yet not name, doesn't mean it wasn't there. What I paid for those strings, what the clerk looked like, all I can tell you is I walked there myself from the college up the street -a college that went bankrupt and is also not there anymore. The buildings are all now privately owned and there isn't clue there was a school there. Did I not spend 4yrs of my life there though I can't show you it exists now?
Now this is not to pick on any one person, but come on folks, this memory lapse meme only holds so much water for so long.
The OP says that another musician friend called them flatwounds, the friend who was more experienced was probably correct. Or perhaps they were tapewounds (since the OP mentions them being black) that the friend just refereed to as flats.
I concur with your answer to your statement, sxsaxsx.
The OP also said that when they did buy their first set of flatwounds expecting these square strings they received roundwounds with a plastic coating instead.
Well flatwounds aren't roundwounds with a plastic coating, so that is another episode of the OP misremembering something. Here the OP could be remembering Elixr strings which have a polymer coating.
You accuse me of misremembering then answer your statement by saying they could be a particular brand. Well, if Elixer's had the previously mentioend tan/gold packaging 35yrs ago, then yes, they could have been Elixers.
And right, so it's not the case that 19yr old noob asks a store clerk for flat wounds and takes what is given on good faith and feeling cheated at the time. It's a modern-day misremembering of times gone by.
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This whole distancing and 'othering' with "OP states" that several folks are on to not only here but in that drewKore thread from years ago. Is that normal?
People engaging in conversation with each other usually speak with names, handles, abbreviations or even 'you'. People who are talking at or down at others use weird 3rd-person distancing things. There's probably some smart-person technical term. Maybe I've just never seen anything like this before. It's a strange dynamic, like some kind of trial lawyer-talk thing "Plaintiff of suit is clearly senile and cannot recollect yesterdays meal, much less events of last week, your honor." "Yes, your honor Plaintff this, that." Never address another by name or as a person, just an object or number, 'an other' is what the behavior seems to come down to from some form of self-portrayal as lofty and neutral dispenser of universal truths and ideals to the hopelessly befuddled masses?
That I am posting this in sxaxsx reply is not to single you out, sxaxsx, as the whole thing seems pervasive beyond this thread and always seem focused on making 'the OP' to be out of their mind. And sxaxsx, I do not take your post disrespectfully and hope you do not see this so as well.
Between this and DrewKore's thread, this oddball topic turned out to elicit some very unique displays of less than admirable posts to the launching of some wonderful flights of imaginings. That the preponderance seems to weigh on 'crush the absurdity' than 'ponder the possibility' is disheartening.
Like I said awhile back, Gaslight was a cool movie. Charles Boyer is always awesome. It's too bad Ingrid Bergman's character amounts to little more than damsel in distress that needs saving, but that was the era. A cool modern day re-telling would likely have Ingrid catch on to the trick, rig the gas lines to explode while she happens to be away with an alibi. lolz.