Cotton Pickin' Pillowcases!

I need your help, you guys. Here is the backstory:

So a few years ago, Big Daddy and I decided to redecorate our bedroom. By that I mean, change out the bedding and window coverings. So we bought a pale gold (maize, not metallic gold) comforter and pale yellow sheets, gold microfiber suede curtains, and dark red accent items (shams, curtain swag, etc). I bought 2 sheet sets. One was 300 thread count cotton, one was 220 thread count cotton. Then, I was at Target one day shortly thereafter, and I found some adorable sheets that were just the right shade of pale yellow and they had an embroidered border on the top sheet and pillow cases that was dark red leaves. I LOVED that pattern, and it brought in the dark red accents. But they were only 180 thread count cotton. So I passed on them. But twice more I went to Target and drooled over them. So I finally gave in and bought them.

Well, as it turns out, those 180 thread count cotton sheets have ended up being the softest, smoothest, coldest sheets of them all. You know what I mean by cold, right? When you lay your head down on cold sheets, it almost repels your body heat. There is no friction or fuzz. It's just crisp coolness. Back to my story.... How could this be? The 220 thread count set we bought are horrible. Very rough. The 300 thread count ones are OK. They're reasonable. But when we put the 180 thread count set in the wash and put on the other ones, neither of us can sleep on those pillow cases. They're just not cold and crisp and smooth enough. Only the 180 thread count ones will do.

Well, flash forward 3 years. My pillowcase got a small tear along the seam where the edge pattern meets the main pillow case. I tried to sew it up, but it tore again. And after another round through the wash, it became a huge t-shaped tear, half the length of the pillowcase and along the whole seam at the top. So it's not fixable. The cotton is just too fragile now. But none of my other pillowcases are soft enough. I've tried buying higher and higher thread count pillowcases (400 and 600), but none of them are as slick and smooth as my tattered one, not even after several washings. So what gives? There must be something other than thread count that makes cotton linens soft. Does anyone out there know? Has anyone worked at Linens 'N' Things and been made privilege to this secret information? Because it is secret. I've spent several hours on the internet trying to find an answer to this question, and all I can come up with is that some weaves are softer, some thread lengths are softer, etc., but no details. Nothing to guide me to making a fantastic pillow case replacement purchase.

HELP!

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