I spoke with a clothing store man in the know recently about this. Apparently, the all cotton version is much cheaper to produce but can be priced the same as the cotton/wool mixture often referred to as Viyella. As younger or newer customers enter the market, the quality difference is lost on them and the resulting windfall goes to themanufacturers. While I do not mind a cotton flannel shirt myself (They are less warm), I lament the abatement of the cotton/wool shirt.

For the moment, Acorn fabrics still makes a beautiful and luxurious selection of the cotton/wool mixture.