I have a sheet fetish shared by four of my best girlfriends, and our combined obsessive-compulsive behavior (and significant financial investment) brings you this news today:

The best sheets ever are microfiber — and you can get them at Costco for $99.

Buuuuuutter, I tell you. Cool-in-summer, warm-in-winter, soft, thin, butter. Toast should be so lucky.

Research: we’ve tried Frette, Peacock Alley, Hotel Collections, Williams-Sonoma collections, Ralph Lauren, Matteo, Pratesi, zillion-dollar linen (OK, those I like), and the rest. I spent a year doing a story about Supima cotton and what it means to the universe. (Did you know that Egyptian cotton is not actually as nice as Pima, or Supima, cotton?)

Microfiber is softer than all of the above, and it’s  just starting to catch on. The spa set is already on it: these are the sheets used at Sanctuary, the Boulders, et. al. Comphy makes microfiber sheets that you can order online. Jennifer Adams Home also makes them, and they’re sold during special events at Costco. (The schedule is here.) You can also purchase them from Jennifer online, but then you will pay $415 instead of $99 for the exact same sheets, and who wants to do that?

Cindy and I each picked up a new set on a weekend shopping whirlwind that also brought us to the sale at Off 5th Saks Fifth Avenue, which is crazy, and you need to go. Sale items are an additional 50% off, which means that I paid $26 for a cashmere T-shirt that used to cost $150. It’s a perfect basic for fall-winter-spring, also sold in pink and other shades.

Mine is black, natch.

This French Connection striped T-shirt was $35.

And check out the studly cuffs and hem of my new Michael Kors sheath dress — formerly $250, now $67.

Find an Off 5th Saks Fifth Avenue near you here. The sale ends Aug. 14.

P.S. My mom taught me this clever trick: save the clear plastic cases that come with new bedding, and use them to store seldom-used blankets and linens in your linen closet. It keeps the dust off and the just-washed scent in. (I tuck in a dryer sheet for good measure.)

Oh — and never buy a duvet insert from Ikea. They seem to made of cotton balls and aren’t sized correctly for standard duvet covers.

That is all. Have you tried microfiber sheets?