Information from their website:
“Marr Haven Fine Grade Wool Yarn comes from our Merino-Rambouillet sheep; you can feel and see the luxurious softness. As explained below, our yarn is 100% Chemical Free and can be classed as ‘Organic’ Wool & Yarn. All Marr Haven yarn is mule spun to keep the natural elasticity of fine wool.”

Marr Haven Wool Yarn will take wool dyes beautifully; the Light Grey and Medium Grey will give a deeper richness to a color. The natural processing of our yarn allows it to felt as well, no bleaches are added so the Natural (off-white) does felt.

Only premium wool is sent for cleaning. The cleaning process used on our wool is called “scouring”; using only soap, water and salt. Many wools are cleaned by “carbonizing”, using an acid process which burns up bits of hay chaff while cleaning the wool. Some wools are bleached as well, ours is not. We believe the scouring process, which retains some lanolin, is kind to the wool fibers and to the wearer of the finished garment.

If we want “LIGHT GREY” yarn, 10% natural colored dark wool is blended with the white wool during carding. “MEDIUM GREY” yarn is 40% natural colored dark wool blended with white wool. The “NATURAL” is just that; natural white color, cleaned naturally.

The same fine-grade wool is used for our Heather Colors; the shearing, skirting and scouring process is the same. The natural wool is blended with dyed wool to make the Heather Colors. They are considered low chemical due to the dye. The five Heather Colors of Burgundy, Blue, Green, Lilac and Light Heather.”