The infinitely funny and talented Daniel of the Manhattan Nest blog chronicles his search for a gray linen duvet at http://manhattan-nest.com/2011/08/26/my-inspirational-story-of-hope-and-perseverance/ Unwilling to spend $200+ for the duvet at Area (http://www.arealinenshop.com/heathercementduvet.html) and unsatified with the one at cb2, he finally found one at Muji, but I think all their brick and mortar stores are in NY and online they only seem to have a white duvet cover.

If you don't mind solids, then what is wrong with the RH linens they have now?

I too was in search of the perfect gray duvet, plain or patterened and couldn't find anything I liked or could afford. I finally succumbed to sewing one myself. I found a beautiful striped gray and white sheet by Martha Stewart at the thrift store of all places. It isn't linen but it is a real heavy sheet and has the look and feel of linen. I backed it with an old white linen sheet I already had and it is the best looking duvet I have ever owned.

Libeco Home (sometimes you can find them on sale) and Rough Linen.

Libeco Home has done similar stripes in the past; perhaps they have something now.

I second Libeco Home. I found this etsy store AVISAOrganics's but I can't speak for the quality of their products.

http://www.etsy.com/listing/81719578/free-shipping-linen-top-sheet-linen-bed?ref=pr_shop

I was just at Target, actually, and they had a linen duvet cover. It is a blend, however; I'm not sure if that would bother you. Personally, I like blends better b/c it keeps the linen from wrinkling too much. Anyway, I think they were clearance too.

MATTEO is usually expensive, no doubt...but the linens are gorgeous and sewn/dyed right here in LA., and there's a quilt on an amazing sale right now that looks a little like the striped quilt posted above...see http://matteohome.com/shop/product/americana-light-stripe-quilt/
Also there's a back room in their downtown showroom with discounted items.

lepidoptery is right. Restoration Hardware still has two "washes" of unpatterned linen bedding, and it's probably the least expensive source for 100% linen sheets outside a sale.

I have really liked all the bedding I've purchased from Cuddledown, not really sure how their price compares to RH. Those striped sheets were really lovely, too bad they discontinued them. Good luck!

I looked for months and ended up with a pewter colored linen duvet @ charles p. rogers (mail-ordered) from New York:

http://www.charlesprogers.com/european-linen-duvet-shams-p-162.html?cPath=3_15

It's well made and looks great - only caveat is that linen wrinkles.

happyfarmr, love those linen set. I think I am going to order a set in natural. WHen you say pewter color, do you mean the gray they have?

sennis, I just ordered the quilt you linked to. It's not the linen I had dreamed of, but it was such a good deal and the stripes were perfect; I couldn't resist. Thanks for the help, everyone!

http://www.roughlinen.com/
Tricia has great linen bedding, good quality close woven 100% linen fabric.
We went into Restoration Hardware last week and I was surprised at how light-weight their linen sheets are in comparison.
I am biased...