I love the hotel comforters and would like to find something similar for my home. Has anyone bought a duvet or comforter that is white and extra large for a king bed? I haven’t found a white comforter that is wide enough to cover my deep mattress (12").
I happen to find nice ‘hotel style’ ones at ross dress for less. We have a California king waterbed and I usually get that size comforter.
Are you interested in down comforters? Actually, Costco has some pretty good ones for not too much. There’s also a web site called downlite that I ordered my favorite comforter of all time from. Unfortunately they don’t have it any longer.
When we stayed at some Westin Resorts, they said they sold their linens and other things online. You might want to check out this link. Good luck!
https://www.westinstore.com/productGroup.aspx?Hotel-Duvet-Cover
More hotel goods that you can buy:
https://www.hiltontohome.com/category.aspx?comforters
https://www.shopmarriott.com/category.aspx?blankets-comforters
https://www.hotelluxurycollection.com/shop/category/-hotel-duvetsdoonas
Thanks for the help! I just measured my mattress and it is 14+ inches deep! Why did we buy this??? Nothing normal fits it! (We’ve had it for a few years so I can’t change the size. Lol)
Nordstrom carries the Westin Heavenly Bed linens etc. If what you buy does not fit your specific mattress, Nordstrom’s returns are heavenly easy! 
Marriott has their bedding and accessories for sale online, too at shopmarriott.com.
You could try the Company Store, thecompanystore.com. They carry comforters in a size called “Oversized King.”
Cuddledown of Maine sells oversized king comforters in a variety of weights and fills.
Second the recommendation for Cuddledown of Maine. You can get oversized comforters there.
http://www.cuddledown.com/ShopCategory.aspx?ID=70,3165
We rent our vacation place for a month in the summer. The realtor who handles the rentals told me to get sheets and towels from one of these two vendor. (Seems that high-end renters, even when renting a house, want hotel-type sheets).
http://www.linenplace.com/boutiques/product-ideas/mascioni-towels.html
http://www.pioneerlinens.com/Comforters
Delta Air Lines also has Westin Heavenly Bed linens aboard its international Business Elite service.
Interesting. I can’t buy anything that isn’t made for the deep mattresses.